Great grandfather's old Omega, bought in 1950s. What is it?

Hi everyone. My grandmother recently gave me her father's (my great grandfather's) old watch. All I know is that it was bought in Italy in the mid-late 1950s. After having done some basic research, it appears to resemble a Tresor. I have no idea if it's been modified or repaired.

I would like to get it restored so I can wear it as it has a lot of sentimental value. I'm reluctant to try and remove the back myself - I'll leave it to a professional to do this at which point I imagine I'll be able to see a serial number.

In the meantime, I'd appreciate any assistance in identifying the model and whether or not it is in its original condition.

Thanks!

Hugh

Looks a lot like a reference 2603... see here for example:

https://www.bachmann-scher.de/en/so...ref-2603-12-stainless-steel-bj-1958-5027.html

Any plans to say thanks Hugh ?