Are you wanting to sell it? I think it's very cool that you are the original owner from 1980. If you want to sell it, condition is key, but just know that sometimes you will be better off selling in the current condition, than getting it serviced, maybe losing a few original parts, and then selling a cleaner but less original watch, plus you are out the cost of the service.
If you are just wanting to know whether it's worth servicing or not, I'd service it, using a good independent watchmaker. You should use the forum search function. It is actually quite good, and you will find specific recommendations for vintage Omegas. I would not replace anything, if this is really original. Just clean and service the movement.
Good luck, and if you are wanting detailed info, I'd post a few more picturesfor more info
