Does anyone have this 1920s calibre number please?

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DManzaluni

·Nov 10, 2021

I don't thing it is particularly unusual but it is 23.5mm in diameter.

My expert opinion is that the stem is missing and I would like to find a bestfit part number

I don't think there is anything unusual about the layout

 

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Canuck

·Nov 10, 2021

My guess would be Omega12 ligne. No calibre number. See image from Ranfft. It looks like the Omega 100, but the wire lugs tell me it is the earlier 12 ligne, from the late 19th century, up ‘til about 1925.

 

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DManzaluni

·Nov 10, 2021

I never figured out how to search Ranfft, - I always get either page after page of irrelevant results or none at all. I certainly couldn't do a search by diameter, which on this is about 23.5mm (see spacer!) whereas the cal. 100 is the more normal 26.5 for a 13 ligne.

Do you think the stems are probably the same?

 

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mac_omega

·Nov 10, 2021

IMO it is a cal. 23.7 and not a cal 12´´´

 

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DManzaluni

·Nov 10, 2021

mac_omega

IMO it is a cal. 23.7 and not a cal 12´´´

Yes, that might well be the one, though he does say, slightly ominously for someone looking for a stem "The first 23.7S had different ... click- and crown mechanisms" Still, all the 23.7s movements look later and slightly more developed with 3 adjustments so the W25 should be OK: The sub seconds does look like a mid 20s design rather than a late teens

Edited: Nov 10, 2021

 

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mac_omega

·Nov 10, 2021

DManzaluni

Yes, that might well be the one, though he does say, slightly ominously for someone looking for a stem "The first 23.7S had different ... click- and crown mechanisms" Still, all the 23.7s movements look later and slightly more developed with 3 adjustments so the W25 should be OK: The sub seconds does look like a mid 20s design rather than a late teens

I am confident that the stem will work on all versions of 23.7 but I am no watchmaker. Al @Archer will chime in soon I guess and he has access to the Omega extranet and will be able to tell about the compatibility of the stems. Good luck for your project.

 

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DManzaluni

·Nov 10, 2021

Possibly nothing more than a bit curious that it came in with an unmarked trench watch with a screw in bezel and swing out movement that has a bridge layout which looks suspiciously like a Patria

 

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JimInOz

·Nov 10, 2021·Melbourne Australia

mac_omega

IMO it is a cal. 23.7 and not a cal 12´´´

I agree.

 

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JimInOz

·Nov 10, 2021·Melbourne Australia

I think the stem for all three would be the same but I don't have a Bestfit catalog to check.