The watch obviously has a LOT of sentimental value to you.
& I fully understand not wanting to pay a lot of money for a service/overhaul when it can be done for a more reasonable cost elsewhere.
I'd pack the watch up ( without papers box etc etc ) & send if off to Omega in Switzerland.
They'll give you a free estimate for the work required. If you find the price to be too much, you can simply ask them to return the watch.
HOWEVER, if you let them do the work, the watch will come back looking like brand new. It will have a full 2 year warranty from Omega & you will get all the old parts back too.
You will basically get a brand new watch for your money.
Hit this link to see an example of what Omega did with an old watch of mine
IF, you send it to Omega, they will ONLY do a full restore/repair job.
Whilst I'll admit the Omega prices are not cheap, they are ( IMHO ) exceedingly good value.
Since you are based in the UK, another option available to you is to use Richard West. He regularly posts on this forum under the name "West Repairs" & is based in Kent. I'm sure you can chat with Richard & he'll probably be able to do only the work you want doing. Should you not want to have any cosmetic work done, this may be a cost effective way to achieve that.
If it was my watch, after 14 years of faithful service, I'd give it the "Full Monte".
Let us know what you decide & how you get on.
Steve