I'm with "ppytprs" - up to a point, at any rate...
Better to replace with new, or a magnetic system.
Over the years I have midi-fied a number of ex-Compton wood-core keyboards.
The first pair that I acquired came without the original key contacts anyway, so I fitted reed switches and magnets.
Some time later I acquired a pair that still had their original contacts attached – albeit damaged or incomplete. One look at these “cat’s cradle” arrangements was enough to convince me that only a masochist would attempt to restore them, so I removed them and fitted reed switches!
At that time I was a firm advocate of reed switches and magnets, but more recently I did some experiments with photo-interrupters (opto-switches) and did a proof-of-concept exercise by fitting them to an ex-Compton keyboard.
In my opinion, this is definitely the way to go. The photo-interrupters are so much easier to adjust than reed switches and magnets, and there are none of the hysteresis or cross-talk issues that you have to contend with if you employ magnets. Also, they are cheaper!
Bite the bullet! - You won't regret it!
Graham