Hey David,
If you post up some pictures (front and back of case, dial, movement, any stamping inside the covers) we might be able to offer some better advice.
If it’s gold, the value is sadly in the melt value of that gold.
The numbers inside the watch can be used to get an extract of the archives from Omega - this costs somewhere around £150 (or more now?).
Service cost on the movement is, from a good watchmaker, typically similar to a three hand wrist watch - £250 to £600 depending on who does it.
Cracked enamel dials can be stabilised and repaired , but it’s expensive, and the results can be variable.
If it has sentimental value, and you’d like to keep it and have it running, I’d suggest a service, and depending on how bad the dial is, keeping a eye for a replacement on eBay - you might not find an exact match, but there are quite a lot floating around.
cheers
Chris