1968 Barracuda fastback..formula S 383/4spd..Restore or not?

You already answered the question I always ask. If you can do all the work, then it is feasible to restore it without worrying about how much you have in it when you are done. Not having a fender tag will affect the value of the finished car, but unless you want a matching number trailer queen, you probably don't aren't worried about that. Build it however you want.
BUT PLEASE SAVE IT!
I’m trying to get more information from the guy I got it from. Trace the owner history to see if any more information exists. Maybe a previous owner has the fender tag.