The Nylon 66 is indeed a classic and well worth fixing. However, be aware that it is a complicated firearm with lots of very small parts. Basicly, its a pain in the butt to work on. I'd recommend one of the disassembly/assembly manuals as detailed instructions are needed. The Gun Digest series volume on rimfire rifles is excellent and what I use when I work on these rifles.
For parts try Bob's Gun Shop. P.O. Box 200, Royal Ar,71968. Phone (501) 767-1970. He specializes in parts for antique, obsolite and discontinued firearms. Prices are very reasonable and he has a very good selection of Nylon 66 parts.
Good luck.