Help identify this Omega PW caliber

[Dmitry]

Hello,

I have come across an Omega pocket watch (18 size, 7 jewels) and need your help identifying the caliber.

Serial number according to https://serial-number-decoder.co.uk/omega/omega.htm mentions 1912 production year, and that's about it.

I need to order a few parts, but without the caliber I won't be able to order the missing crown wheel or a new balance staff.

While looking great on the ourside, solid silver case and all, insider there was a nasty surprise, I have never seen a watch so dirty or corroded. I suspect salt water ingress, and then someone seems to have dunk the whole watch in some sort of oil.

Any help is highly appreciated.

Thank you.

Edited January 24, 2022 by Dmitry
added size

[Klassiker]

Is this it?

http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&2&2uswk&Omega_19LOBNN

[watchweasol]

Hi according to the database its dated between 1913 and 1914    and is a 19Ligne

[Dmitry]

8 hours ago, Klassiker said:

Is this it?

http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&2&2uswk&Omega_19LOBNN

YYep, looks like it! I think the 26513 stamp refers to the keyless setting swiss patent. I noticed the other Regina PW I posted about earlier has the same construction, which makes sense as the calibers are only a few years apart and Regina Watch Co was replaced with Omega later on.

[Klassiker]

16 hours ago, Dmitry said:

YYep, looks like it! I think the 26513 stamp refers to the keyless setting swiss patent. I noticed the other Regina PW I posted about earlier has the same construction, which makes sense as the calibers are only a few years apart and Regina Watch Co was replaced with Omega later on.

Interesting, thanks for posting it.