OTHER PARTS DEALERS: Can't find it here? Try one of these guys. These are all reputable people that I have personaly dealt with and can highly recommend .
TFSource.com Has Japanese Re-Issues, Japanese Binal Tech, loose complete G1 Transformerers, and G1 parts. Also has lots of information and pictures of some really rare G1 Transformers.
Transformerland.com Has large ID and reference section.
Artsenal's Transformers Parts Trading Site for those of you who prefer trading.
PARTS IDENTIFICATION: For one of the best sites on identifying Generation 1 Transformers parts HAS PICTURES OF EACH PART Reworks Parts Identification Page
VARIATIONS AND GENERAL INFORMATION: Did you want to know about the 20 different variations of G1 Optimus Prime? Not sure if that Hot Rod gun you found at the local flea market is original G1 or a re-issue? Then check out Freds Workshop. He covers the entire spectrum of Transformers variations from original G1 to currently released merchandise.