Parts are easy, the skill and knowledge to install and align the players to factory spec not so much anymore.
I have a wonderful Kenwood DP-M7730, a cartridge-based CD player from 1992. (Six CDs per cart. I think it cost ~$400 then, which is something like $5 million today.)
Anyway, every single unit out in the wild is now out of alignment. (There are always listings for these and their cousins on ebay, the sellers always saying they work "good." Not. Most units in the wild will play a coupla discs out of the six in a cart, but never all of them.
For years I've been meaning to fix (i.e., align) mine. But I keep putting it off, because the cost of aligning it is more than it cost new. The biggest obstacle is you have to make your own alignment disc, because the ones made by Sony back in the day are no longer available. (Occasionally one comes up on ebay but they want $75, and I'd never pay that to get a possibly scratched and nonworking disc.)
And then you gotta buy a scope. The old Tek/HP ones which I used at school and work years ago are way too expensive. And I've been reluctant to try those $300 Chinesium digital scopes, which seem to be all menu driven. (As opposed to rotary switch driven. I'm afraid if I apply to a $300 Chinese scope the forces we used to use to twirl all those Tek switches, the thing will break in my hand.)
TL;DR: I have the expertise, but not the patience nor the willingness to spend the money. But those Kenwood cartridge players are beautiful. Plentiful in bars back in the day. The Kenwood carts players are also more amenable to restoration than the Pioneers, which I think have a ball bearing in their cart, which makes them failure prone.