I was going to say not much at all, I suppose since I’m relatively new to the tinkering game. (It was my little lockdown exploration.)
But now that I think about it, a lot has been tinkered with. The Ricken backer 4003S got a treble pickup bezel, “vintage” knobs and a toaster in the neck position. The 76 Mustang got a new pick guard. And I kind of went to town on the 73 Precision, feeling comfortable to do so since it was already pretty messed with quite a bit. I replaced the pots, knobs, pickguard and pickups. Roadworn Jazz got a new refin (not by my hand). But the Ray, the 75th Anny Commemorative P, the AVRI P, the RA Deep 4 and the Lakland HB-30 remain stock, and will forever do so, I suppose.
So no, it’s not a regular thing I do. More like a phase I’ve just emerged from.