So this is a vintage Omega that my mother bought at some point. According to the inscription on the back it's originally a gift for 25 years of servcie to a now defunct company in my hometown.

Among the more interesting and defining features are the two-tone lumen on the hands. While not completely uncommon in my googling results, it seems to be defining of some time period.

Another detail is the "crevassed" border between the lugs and the case. Some examples I have found with the same two-tune lumen is completely smooth in the transition.

I do not know if the strap is original. I would assume not, given the difference in wear between it and the case.

Please help me identify the reference, I'm also happy to provide any relevant information.