As the owner of a ridiculously awesome 62 SG/LP jr, I had it re-fretted and didn't think twice about it. Didn't hurt that I had one of the best repairmen in the US do the work (Alex Glasser @ironhorse Instruments, you are a true artist).
Plays like, well, the best guitar I've ever owned. Not selling in my lifetime... but if anyone had an issue with missing nibs, we could laugh about it over drinks while they lust after the guitar they will never own.
IMO If it needs a refret - get it re-fretted. Forget the nibs. YMMV of course