Omega No. 27 Clasp for Seamaster Chronostop

I just purchased a Seamaster Chronostop Driver. Based on multiple recommendations found on this forum, the plan is to secure a replacement perforated leather strap from Steveostraps. Before doing so, I want to make sure I find a correct clasp:

1. Omega No. 27 Clasp - Is the Omega No. 27 clasp correct? Are all No. 27s the same design? My Seamaster Chronostop has a 22mm case lug width. I think the Genève Chronostop lug width is smaller, thus the question on clasp size/design.

1. Clasp Availability and Price Range - Are there any recommended suppliers for an Omega No. 27 Clasp beyond normal sources like e-bay? What is a fair price range?

1. Strap Fixing Plates - Steveostraps offers an alternative to the strap fixing plates. I understand the fixing plates are hard to find which makes sense given most were probably thrown away with the old straps. However, I would prefer to use the proper fixing plates if possible. Recommendations would be appreciated.

Thanks in advance for the help and expertise!

Hi, don't miss: https://www.ebay.com/itm/286439169343?_skw=Omega+27+clasp&itmmeta=01JQENV7KR9VDT2E99X40CT5Y5&hash=item42b11add3f:g:BnMAAOSwqWJn1HZe&itmprp=enc:AQAKAAAA8FkggFvd1GGDu0w3yXCmi1cX6GL91Z58qDVHYFem666YCfIHL/tZ5iuSCCL4W9NIntusCmwacjx2rSsddfYYVHRFiKNuySn5X0Ru430vC6UqIC0HKaevttAHVktnXyeGR+RzjrXBYNmZu0uKStd8WqwlSas+Rlb7dGGp/kkPD4tnZsq6IsYI0Sb78C4S+CxX3Nd4cUnbklIoO+enm5/vZbB2mBf5uMzWrvrqdMlLRl0NQoh7jVEXa1YLr1WDU/5BzdtTDGHmwhesfGzmF092p8ZcruaFj7vGgBtHK+c89pjP15VwIAq6+JQeuSUUVq90tw==|tkp:Bk9SR4r67NW7ZQ

https://www.ebay.com/itm/1164569313...uF2sytcostYSIz2XS0MXcdK+U=|tkp:Bk9SR4r67NW7ZQ

Slight tangent — I don’t believe Omega made a driver-style chronostop with date in this particular case.

Are you sure you don’t have a movement and refinished dial from a geneve chronostop that has been adapted/transplanted into a seamaster chronostop case?

I have never seen this kind of inner ring before in a 145.010. Also the caseband does not look right to me. Interesting watch.

kind regards Max

Seems like a 145.007 case

Yes, that is possible, 145.010 has 18 mm lug with, 145.007 22 mm. But that Roulette style inner ring?

kind regards Max

It very well could be a Frankenstein??? Glad I posted a picture and want to learn more. Sincerely appreciate the feedback given you guys have forgotten more than I will ever know.

I impulsively bought it this week because I really liked the aesthetics of the watch, especially once I noticed the 90° dial rotation and subsequently found out that made it a “driver” variant worn under the wrist. I own a ‘72 and an ‘85 Porsche 911. The watch seemed to be a natural extension to that interest.

I found this thread https://stories.omegaforums.net/chronostop-part-3-145-007-145-008/. It has a photo of a similar dial configuration (although the example in the photo clearly has a 145.008 third crown). Beyond the previously stated oddities, I cannot find another web search Seamaster Chronostop example with the day function???

Once again, really appreciate the forum’s expertise and help in solving this mystery!

Very Interesting! Ashley Budgen’s articles are amazing. Looking forward to reading/learning more. However, two references pertaining to my specific circumstances jump out for me:

From Part 1: “In this first part, we will look at four specific references, the original 145.009, the 90-degree rotated version for under-the-wrist wear reference 145.010, and their respective calibre 920 powered date versions, the 146.009 and 146.010. While it may seem a bit confusing looking at all these references, they all refer to the same physical case design and only vary by date and orientation. So any Geneve chronostop starting with 145 should have no date and Calibre 865, while any starting with 146 should have date and Calibre 920. Similarly, any chronostop ending in 009 is the standard orientation, while any ending in 010 have the dial rotated 90 degrees.” [emphasis added]

From Part 3: “The Seamaster Chronostop only comes in one dial, and accordingly only in one movement across both references, the Calibre 865”

Correct me if I am wrong, but that points to two possibilities:
1.) My watch is a complete fake or . . .
2.) As masteroftime mentions in his post, someone used a Genève Chronostop date function Calibre 920, somehow erased the Genève markings and replaced them with Seamaster markings, and added an outer bezel in a Seamaster case???

I am a layman so in need of advice. Are the next steps opening the case to retrieve movement numbers and close inspection of the Seamaster script using a loop?

Close up photos . . .

Thank you, @sathomasga. Our posts crossed. I’m no photographer, but do the photos I posted confirm the dial is repainted? My layman’s eyes seem to think so???

Agree! That seems to confirm @masteroftime’s initial assessment.

I know condition, authenticity, collectibility, desirability, and many other factors dictate value, but now that we have a better idea of what the watch is, and is not, what would be a reasonable price range?

A fair and legitimate point @sathomasga. It appears authentic Omega Chronostop watches are “buy-now” listed on e-bay for $1,500 - $2,500, with Chrono24.com generally in that same price range. Unless you (or other forum members) think otherwise, that sampling should give me a sense of prevailing market prices for a “correct” watch.

I sincerely appreciate the expertise and timely guidance!!!

That makes sense and gives the horseshoe and hand grenade answer I needed. Thanks again. I really appreciate the help!

I do not want a case of wishful thinking to override fact and reality. However, I was able to consult with a reportedly knowledgable watchmaker interested in Chronostops. As an added bonus, he claims to have inspected my watch for a prior owner. Like multiple other appreciated and respected watch experts/enthusiasts on this forum, he has never seen my configuration listed in any of Omega’s retail publications and catalogs. However, he has come across at least three other Seamaster Chronostop watches configured with the Calibre 920 date reference.

Additionally, he is of the opinion that my dial is not refinished, providing dial examples (although not Chronostops) with similar “Seamaster” script including the more rounded shaped “e”s.

The seller is honest, offering to provide a full refund if I feel the watch has been misrepresented. I really like the watch, maybe paid a slight premium but not a king’s ransom, and I am a layman enthusist, not a serious collector or speculator. I also like the mystery associated with the watch and the research/learning opportunity that brings.

Having said all of that; before my return opportunity closes, does anyone have anything that clearly shows Omega never sold Seamaster Chronostops with the date function or further evidence that reasonably indicates mine is a Genève retrofit?

Everyone’s input and guidance are very much respected and very much appreciated.