Okay: Low use vintage gear/gear wear phobia,...
are like two sides of the same coin. Consider, that if the previous owner had used the gear very hard & very often, then we would not be scoring the "mint" vintage items, like we are.
So, you score a 20 year old machine, that has the realistic equivalent use on it of a 1 or 2 year old machine, and of course, it's natural to NOT want to used it, wear it out, or adulterate it in any way, lest we don't have a "mint" machine any more. A paradox, indeed. This, of course, is a natural protective instinct, but at a certain point, the pedal must hit the metal, and the rubber must meet the road,... otherwise, you got yourself a 70 lb doorstop or paperweight,... or 3-D sculpture, at best.
Use it!
I know, I'm the WORST about this. I literally have DOZENS of viable tape recorders, the bulk of them DON'T get used, for the most part because I don't have my "chops" worked up, worthy of recording. And, like you, there's something inside us all that doesn't want to put wear or smudges on an otherwise pristine and mint machine. However, it's inevitable.
As for me, like I said, I hardly ever record, despite being FULLY LOADED on gear, tape, accessories, instruments, etc. I do practice, however, mostly just going through the motions, with no musical framework whatsoever.
SO, I TOO just decided to SET UP, TUNE UP, LOAD TAPE, and PRESS THE RED BUTTON! Just last night, I brought my LIKE-NEW-ultra-MINT 488MKii into the bedroom, set it on a firm box on the bed, tuned and plugged my guitar, and recorded 4-simul tracks of guitar onto the 8-track cassette. No rhyme, no reason, but I was rolling tape.
It's funny, that as "smooth" it seems my playing is when I'm just "noodling around", when you press RECORD, it seems that there's a self-conciousness that sets in,... yes,... even for me, a 20+ year recording veteran. I choke just like it was my first time recording.
Well, FWIW, I know what you mean, by having this desire to record, and yet not wanting to put any unecessary wear on the machine. But, it's inevitable, you MUST RECORD.
Keep in mind, that if you're only using your machine sporadically, there's really not a lot of wear you're putting on the unit. If, however, you're using your machine 8 hours a day of hardcore recording, of course there's some wear that gets put on the machine.
Again, it's inevitable: You MUST RECORD.
Otherwise, take up knitting, golf or tiddley winks!