Is this a franken 18k gold Omega?

Hello, this is the first time I post on this forum. I have a question about an Omega watch that I received from my father. It has a cal. 601 and the case is 18k gold. I don’t have any more info about it. But what surprised me is that when I opened the watch I noticed that in the inside of the caseback there is no omega logo. The only inscription on it is the reference : 20443 (that don’t match up with any omega reference) and the inscription 18k 0750. In addition, as you can see below, the fixing of the case is strange. All that to say that I assume that this watch is a Franken. However, not having the necessary knowledge, I preferred to ask the question here in order to be sure.

Thank you in advance for your responses.

Hi mate, welcome to the forum 😀

I don't think it is a franken, but the case is likely to be a locally produced one - not uncommon on midcentury gold Omegas. If it had been a Swiss made case, there would have been two gold hallmarks on the case, typically on the rear of the lugs.

Hey ConElPueblo thank you so much for your fast answer! 😀

That’s also what I thought. And when doing some research, I found this thread :
https://omegaforums.net/threads/omega-made-cases-vs-contract-cases-in-early-watches.59442/

So if I’m correct this case would be a locally made case without the authorisation of Omega?

Ps : I found some Omega’s with cal 601 on Internet that also don’t have the Omega Hallmark on the inside of the caseback and I don’t know what to think about it.

Here are the links :

- https://www.chrono24.fr/omega/omega-geneve-cal-601-gold-192k-800-mm--id14436343.htm

- https://www.catawiki.pl/l/35906101-omega-geneve-cal-omega-601-gold-18k-mezczyzna-ano-1966

I think it was most likely with the blessing of Omega. They were more interested in selling movements to a country where they'd be cased locally than sell none at all 😀

Thank you for taking the time to answer to my questions and share your knowledge with me. I appreciate it! 👍