Vintage value

Hi y'all.
Apologies for leaping in here with no real previous ( have been using TAG forum).

My wife has a vintage silver Omega De Ville from about 1974 that has been carefully 'looked after' in a drawer for about 35 years!!
.... and now she's wondering if it's worth getting serviced, repairing if required and wearing again.
Any idea what second hand price she might get on it ?
I've had a look around but can't find anything.
Anyone ? Would be very much appreciated.
Cheers.
Dave

(p.s. wound up and has been running fine for 20 mins!! )

That's what keeping it in a drawer does for you

It's still going, 3.5hrs later

She tried it on claiming it was too small.
Now strictly speaking...
Having managed to close the clasp her wrist immediately swelled a small margin.
Eventually, following the production of the hacksaw, we managed to get it off AND save the wrist.
There are some spare llnks around somewhere. I'm sure I've seen them at some point in the past and vaguely remember thinking I'd got no idea how to add them....