Personally? I'd stash the original numbers engine (or just the bare block) get another similar engine to build (you didn't mention what it is?) assuming it's a 383 you can get another one, or a 400 which looks the same externally, and build it for fun with a stroker kit, etc. and have a bunch more power/fun.

Shouldn't cost a ton more than rebuilding a stock engine with what's available off the shelf today. This way you can have fun beating on it and not worry about damaging the cars numbers matching status.

.02