I had several older vehicles (66 Mustang, 73 Scout, 79 CJ7) and while I did some stuff on them I never got in very deep. And on the rare chance I tried something more advanced, it went sideways and caused the thing to sit in the garage, broken, for a year or more. Like when I tried to upgrade the distributor on my Mustang. Popped the old one out, went to drop the Pertronix unit in...wouldn't fully seat. Old one wouldn't seat either. And that's how it sat for probably 18 months. I eventually solved it, but was again scared to touch it further. Plus with a nice older mustang the odds of me de-valuing it were pretty significant.
I've only had my TJ for going on 3 years, but there isn't really any project I won't attempt (other than body work or any sort of rust repair). Just takes a little courage and a lot of YouTubing.
This is a good post- you can do so much to these without touching the engine or risk disabling it.