If it's an investment vintage instrument then keep it original. Quite stupidly collectors of such things care more about that than whether the damn thing is actually playable. Oooo look it's got the original frets... worn down to be almost fretless and sounds crap as a result, but yay!
I've love a 70s jazz. But I don't trust myself. In under 10 mins I'd have upgraded the bridge, ripped out the heavy tuners and put in Ultralights, and if it's a heavy one I'd be routing out under the scratchplate too.
But then again... if it's for me and I want to gig it... then why not? I don't think I'd buy anything I didn't want to gig.