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Between 1924, when K. Hattori & Co., Ltd. first used the Seiko brand on a watch, and 1950, when it introduced its first centre-seconds wrist watch, the movements that powered many of the company’s wristwatches were sourced from the Swiss watch company, Moeris.
Those earliest two-hander, small seconds sub-dial wrist watches used 8 or 9 ligne, 7-jewel Moeris movements, with their characteristic banana-shaped bridge design.
Subsequently, a larger 10.5 ligne version of this movement was used in watches produced from the mid- to late-1920s. This movement was known as the cal 10 and although branded SKS, its Moeris DNA is still pretty clear.

Photocredit: http://nakahiro.parfait.ne.jp/moji/sks.html
A new calibre 10A was introduced in 1946 and produced in the Daiwa Seikosha Suwa plant, the evacuation factory used by Seiko to re-establish its post-war wrist watch manufacturing following the destruction of the Kameido Factory in Tokyo.

Photocredit: http://nakahiro.parfait.ne.jp/moji/newcal10.html
This new movement used separate bridges for the escape, second, third and fourth wheels but its gear train layout is still recognisably carried over from the cal 10. From 1948, a further development of the cal 10, the 10B, was produced in the new Kameido factory.
It is not entirely clear to me whether all of these movements were simply bought in from Moeris and re-branded or whether they were built by Seiko under licence but I suspect the former. What is clear however is that they were not Seikosha designs but rather developments of Moeris designs.
In 1950, Seiko debuted the Seiko Super, its first wristwatch with a central seconds hand.
According to the entry in the Seiko Museum website, this new movement “…required a departure from the existing transmission wheel system to a whole new wheel design from scratch.” To me, this implies either that the Seiko Super was an original scratch design or that the train wheel layout was redesigned but in the context of an otherwise existing architecture. I am pretty confident that it is the latter, given the close similarity between the barrel bridge layout and design of the Super (below) and the calibre 10b pictured earlier.
That conclusion resonates more in the context of the received wisdom that the follow-up Seiko Marvel was Seiko’s first wholly original in-house watch. The Seiko Epson Global site describes the Seiko Marvel as “an originally-designed mechanical watch that became the basis for Epson’s watch business”. That being the case, it is probably safe to regard the Marvel as the original modern Seiko wristwatch.
The upsizing of the Marvel from the 10.5 ligne of the Super (23.7 mm) to 11.5 ligne (25.6 mm) allowed for a number of improvements in design, with the focus now on accuracy and the development of a product that could compete in a global market.
The larger diameter of the new movement permitted: an increase in the barrel size, allowing for a higher performance mainspring; larger gears with an increase in the number of teeth, separated by greater distances and allowing for a more even transmission of torque. A larger balance with a larger moment of inertia allowed for a greater resistance to externally-generated forces and an improvement in rate stability.
All of that theory was born out in practice, with the Marvel movement fitted to a whole range of Marvel-branded Seiko watches produced between 1956 and 1959.
A testament to the inherent qualities of the movement is provided by its subsequent up-scaling and transformation into what was to power the first Grand Seiko in 1960.
This lengthy preamble brings us to the traditional point in proceedings where we introduce our protagonist. However, in contrast to most of the accounts presented here, our starting point this time is not a complete watch but a fragment of what was once a complete watch. We begin with a dial, a solitary hour hand and an hour wheel.
I suspect some of you may be thinking that this is no basis for anything other than consignment to the cylindrical receptacle in the corner of the room. My reaction to this dial when it first caught my eye was that it is an object of beauty whose potential shines through the liberal distribution of patina that covers its surface. It is simply lovely and for me there is no question that it should be saved from oblivion. Those of you who read the prologue to this entry (here), will know already that I encountered this dial as part of a minor haul of dubious treasure obtained a few years ago while on the hunt for 56-series movement parts. A sub-set of that haul comprised a small number of very early Seiko Marvel and Crown movements, dials and cases. My original thinking was that within that collection there ought to be a sufficient number of parts to build up at least one complete example of the Seiko Marvel and one of the Seiko Crown. In filtering thorough the assorted detritus, I identified about one and a half complete 17 jewel Seikosha Marvel movements, the dial and hand pictured above and two or three stainless steel cases.
As it turned out, none of the cases were of the correct size to accommodate the dial and so I would be having to look further afield for a solution of how to house the watch innards should I get that far. The two partial Marvel movements also presented some difficulties, principal amongt which, a broken hairspring collet and abused balance wheel and staff for the single balance shared between the two movements.
In the absence of any suitable substitutes from my parts stash, my only option, if I wanted to maintain the Marvel spirit for this project, was to source another functional Marvel movement. The first-generation Marvel movements were not fitted with shock protection but later versions of the Seikosha movements fitted to Marvel and Laurel models benefited from Diashock shock protection for the balance. And so, in concocting my on-the-fly strategy, I decided to try to find a Diashock-protected Seikosha movement for as little an outlay as possible. Within a week or two, I’d secured a suitably bedraggled candidate.
Having extracted the donor movement from its case, it appears we have something reasonably sound, but somewhat tarnished and encrusted with salts.
A closer look around the edge of the movement in the vicinity of the balance shows just how badly contaminated it is with crusted deposits.
The lighting does the movement no favours in these photos – it does not look this bad live – but nevertheless, this is a movement in a pretty poor cosmetic state. Deconstruction proceeded smoothly to the train bridges on the balance side, this being a pretty conventionally-designed hand wind centre seconds design.
We note however that the ratchet wheel is badly corroded on its underside as is the crown wheel to its upper.
I will replace both with clean parts farmed from the other Marvel movements during the reconstruction later on. The train wheel bridge and train wheels themselves parted company with the main plate easily enough but the same wasn’t quite as true for the centre wheel and its bridge.
The centre wheel was glued to its bridge by congealed and very dirty oil. There was no obvious damage to either when the oily sludge was cleaned off but again, cleaner candidates will be available from my Marvel parts stash when it comes to reassembly.
This marks the half-way point and an extended agitation for all parts in the watch cleaning machine. Locating reverse, we start with the mainspring, cleaned and wound into a suitably sized drum.
Some care is required in pressing the mainspring back into the barrel because the tail needs to be aligned with the slot on the inner barrel wall. Reassembly of the movement itself starts with the setting parts.
The centre wheel and its bridge come next, the completion of which was hampered by my serially shearing the tops off the tiny screws that secure the jeweled sweep seconds bearing plate.
I did this three times without exerting anything other than the slightest degree of torque and in the end resorted to a more robust screw harvested from a Seikomatic movement. With that done, the centre wheel bridge can be fitted.
You may have noticed that the escape wheel is served not by a Diafix setting, but by a jeweled bearing capped off by a jewel supported at the end of a figure-of-eight metal plate. I oiled this by placing a drop of oil in the centre of the cap jewel and then lowering it into place before fastening down.
The reconstruction continued smoothly right up to the point where I was to refit the balance.
Unfortunately, the hairspring on the balance that came with my replacement movement was distorted out of plane with the result that the spring would not sit flat. I was unable to correct this problem and, in my attempts to do so, I fear that I may have made matters worse. However, the correct balance wheel was in stock at Cousins and so I placed an order and waited a day or two for the replacement part to arrive. Unfortunately, this ‘new’ balance wheel was supplied with the roller and its jewel missing. To make matters worse, the spring on that one was also bent out of flat. With gritted teeth, I ordered a second. Happily, this one arrived with everything present and correct and the hairspring sitting true.
One of the challenges in regulating movements with fixed stud holders is that there is no easy way to adjust beat error. In my first measurements of the running of this movement with its original hairspring, I was seeing a very large beat error of 3 ms. The beat error is a measure of the difference in the time it takes for the impulse jewel to swing from each of its two turning points to the mid-point between the banking pins. In other words, it is a measure of the difference between the tick and the tock. The beat error is minimised by adjusting the position of the impulse jewel so that it sits half-way between the two banking pins when the balance is at rest. In the photograph below, you can see that at its equilibrium position, the impulse jewel is offset some considerable distance from its ideal position.
In a watch with a balance fitted with a moveable stud holder, this position can be adjusted on the fly in a fully assembled movement as part of the regulation process. However, for a balance with a fixed stud holder, the only way to adjust beat error is to remove the balance wheel from the balance cock and adjust the position of the hairspring on the staff by adjusting the collet position one way or t’other. This necessarily requires a degree of trial and error.
Having worked my way through this process with the new balance, I was able to achieve a beat error of 0.0 ms and an amplitude of about 280 degrees.
With the movement now ticking away happily, I turn my attention to the dial, which you will recall was looking a bit the worse for wear.
Quite a lot of the patina is clearly the result of abrasion-marking from its close proximity to other stuff in storage combined with the accumulation of a healthy layer of grime. My default approach to dial cleaning of glossy or satin dials, particularly those of a light colour is to work the dial gently with virgin Rodico. With the dial supported on a piece of pithwood, I set to work. Here we are half way round.
That’s looking pretty good. Continuing from 6 to 12 results in a presentable dial ready to be fitted to the movement.
I think we are ready to fit some hands. I had an embarrassment of riches to choose from in the gilt Dauphine hand department to pair with the existing hour hand and had soon selected and fitted a suitable set.
You will remember that at the outset, we were missing pretty much everything, including a case in which to house the watch movement, dial and handset. I wanted to pair this dial with a steel case but none of the three cases I had from the box o’ bits stash were compatible with the movement or with the dial size or, most importantly, both! And so I had to turn back to Yahoo to see if I could source a suitable case.
In my attempts to identify the model that this dial would originally have been fitted to, I found one image of a Seiko 14045 with this exact dial/handset combination. However, that model reference is for a gold-plated case and so I set about seeing if I could find a 14044 that I reasoned might be the steel equivalent. As luck would have it, I located an auction for an old stock 14044 fairly easily and landed it with the starting price valuation.
The only fly in the ointment was that it did not come with a crown, and the crown tube diameter on this case was much larger than is typical for this style of watch. And so I had to wait for the case to arrive, measure the tube diameter and then try my luck at finding a crown to fit.
Before fitting the movement to the case, I test-fitted the bezel and crystal to the dial to make sure that both hour and seconds hands would clear the inner surface of the domed acrylic crystal.
Notice that both the minute hand and seconds hand have a pronounced downwards curve to avoid contact with the crystal and to follow the convex shape of the dial. With no contact being made, we are ready to fit the movement to the case. This involves lowering it in from the dial side, securing the movement into the case with the pair of case screws from the balance side and then fitting the crystal and bezel.
The crown sitting to the right is a period correct Seiko crown but comes with no water proofing. The best that I can hope for is that it will be dust proof, but in the meantime, I may keep my eye out for a suitable waterproof crown. With the stem trimmed and fitted to the new crown, we can complete the installation.
The case back snaps into place under determined pressure from my thumbs and it appears we have a complete, ticking Seiko Marvel.
With a suitable strap fitted, the watch is transformed into something really rather classy.
I was half expecting this to end up feeling a little underwhelming, toy-like even, given the typically awful Seiko renderings in their 1956 catalogue, but the reality is that the watch conveys a genuine air of quality, matching the hyperbole of the time.
The arithmetic result of this piecemeal process is comfortably greater than the sum of its parts, with that impression aided, perversely, by the weathered appearance of the dial. An unpromising premise to this particular project has, at least from my perspective, born fruit.
This then is the origin of the species: the common ancestor of the modern Seiko wristwatch.
Fascinating. Thanks for sharing Martin.
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That is just awesome. I hope you can do a first Citizen and/or a first Orient next!
Thank you. I’m glad you enjoyed it.
That came out smashing! What’s the diameter of the watch?
Thank you! The diameter is about 34.5mm I think, but it does not feel particularly small on the wrist.
Hello, As usual fascinating reading. I have what I think is a 1920’s cal 10 but it is marked Seikosha on the movement and SKS on the caseback. Are you able to shed any light on why this might be? Happy to provide photos. Many thanks, Michael.
Hi Michael, I don’t know this with any authority but I understand that SKS is an abbreviation for SeiKoSha.
I’m pleased to hear you enjoyed the post.
All the best
Martin
Very cool, really enjoyed the write up. I love your site.
Another great job! Great read Martin.
Thank you Aleksandr!
Dear Martin, I hope you’re well.
Thank you for your article, as always. For your information, I have the silver dial version of this watch (though a slightly later version, since mine originally came with an S-1 type Diashock movement, rather than one without any shock protection like yours would originally have had, and hence says “Diashock” on the dial), and the case number is 14027. Here are photographs of the watch dial, case, and movement:
https://vi.vipr.ebaydesc.com/ws/eBayISAPI.dll?ViewItemDescV4&item=193521819467&t=0&category=31387&seller=saitama_jp&excSoj=1&excTrk=1&lsite=0&ittenable=false&domain=ebay.co.uk&descgauge=1&cspheader=1&oneClk=2&secureDesc=1
With all best wishes,
Chris.
Hi Chris, many thanks for that. This is all really useful information to help put it all into context. All the best Martin
Also, I have just seen the silver version of your earlier version of the watch in a different case, 14038: https://www.timekeeper.co.nz/forum/market-place/watch-watch-related-market-place/watches-archived-sold/48674-sold-vintage-seiko-“marvel”-1957-—seiko’s-first-in-house-watch
From what I can see, angled-and-flat case-backs, as on the watch in that link from November 1957, are only found on earlier Marvels (and Uniques – I would guess perhaps also for Supers, though I haven’t done a proper survey), whereas domed case-backs are found on both early and late watches. I have an angled-and-flat case-back Marvel from September 1957, and angled-and-flat case-back Uniques from November 1957 and February 1958, whereas I have a domed case-back Marvel from June 1957, and a domed case-back Unique from March 1957 (and earlier Type 10A and B watches with domed case-backs), and many other examples of later Marvels and Uniques with domed case-backs from 1958 and 1959.
I have also come across this dial design with an intermediate dial print/watch type, with “Antishock” on it: https://img.aucfree.com/c672120653.1.jpg
Part of the difficulty in pinning this down is that we don’t really know how many of these examples have been re-cased in the near 60 years that have passed since they were originally produced. The only really solid guide to what was correct is provided by images in Seiko catalogues and advertising material.
I can’t seem to reply to your last comment, so I’m replying here instead. That is true – I have found another example of the same dial marker type, from Martin Backman’s collection, housed in a model 14041 case (as indicated by the URL), but with what appears to be re-done dial text: http://i83.photobucket.com/albums/j302/martback/Collection/Marvel14041Medium.jpg I do think that the same dial type was housed in various different case models, from what I have seen of other models of Seikos.
P.S. Sorry, I forgot to note that my watch has a triangular-shaped counter-weight to the seconds hand (as also shown in the catalogue photo in your post), rather than the straight one which your watch is fitted with.
Hello Martin, very interesting reconstruction, always fascinating.
I also have a small marvel which has a problem with the balance.
Despite my research I cannot find any documentation on the parts of this movement.
can you tell me which reference did you use for the pendulum.
Thank you very much and good luck.
greetings.
Yann.
Hi Yann, I’m afraid I also have no parts documentation on any of these early movements but the Laurels and Marvels all used variations on the same movement with a great deal of parts interchangeability. If you source a few junk Laurels, then you may find what you need. That is the approach that I took. Good luck!
Interesting read. I have done some digging on watches of this era (especially direct driven center hand watches like Citizen Homer / Seiko Marvel and Takano 124 521).
The first center driven seconds watches to come out from Switzerland were from A Schild (AS 1003 in 1940) and Then Zenith I think 133 in 1948 and then Patek 27 SC in 1949.
After this the next movement with a center seconds feature was the ETA 1080 in 1950.
If you look at patents 3 companies supposed applied for and held patents for the center seconds (sweep seconds) invention. A Schild, ETA and Felca. All these patents were issued in the 1941-1942 period.
So I feel these patents expired sometime in the late 1950s or early 1960s and that is when these Japanese movements started appearing. Takano has clear tie up with Durowe a German manufacturer.
All these movements (Citizen Seiko Marvel and Takano 521) have a striking resemblance to each other and also to the ETA 1080 1081. I cannot say for sure since I have no means to access records or to meet and speak with people from the time who can shed light. But this is my understanding of the evolution of these movements. And then yes there’s is One Mr. Moeris in all this.
Hi Nolin, many thanks for your insights. Your theory about the timing of expired patents in the late 50’s early 60’s is not consistent with the appearance of the Marvel in 1950, a centre seconds movement that appears to me a clear development of the Moeris movement. The Marvel and ETA 1080 appeared in the same year.
Hi, the old dial/NOS case combo looks stunning IMHO. I have a 1958 Laurel J14004 with an identical movement, I’m after a stem and crown – do you know what calibre this is or any part numbers? It’s so hard to find good info on pre-1960s Seiko, any help much appreciated, thanks!
Possibly calibre 55?
55 is the larger Lord Marvel.
I have technical sheets at home for many of these earlier movements and will take a look this evening to see what the part number is for the stem. The crown will be much harder because I don’t think there is much information in circulation on casing parts for these early watches. I certainly have nothing myself. For me, it’s been a case of trial and error, mostly the latter.
The stem part number is 351572 used in both the Laurel and smaller Lord Marvel. I couldn’t find the Marvel parts list but assume it will be basically the same as the Laurel.
That is a fantastic help, thank you! Cousins has the stem (indeed a pack of three for £3!), as you say the crown is harder because of the very wide tube but I am not a total purist and will look for something reasonable that will fit. Thanks again