what is the reference of this vintage omega?

Hello to everyone, I'm Matt and I'm new on the forum; I'm in my early twenties and i got into watches a year ago (or at least that was the time when I started buying them).
My grandmother has given me this vintage Omega, which has been in the family since it was bought. I've been doing some research on the Omega website, but I was quite unlucky and I wasn't able to find anything looking exactly the same.
The only thing I know is that is made of gold, and I'm quite sure it is from before the 60's. I didn't open It because I didn't want to ruin it; I'm going to get it serviced after the xmas holidays.

Thank you for your help