I use Roberts Motor Parts and Andy Bernbaum for body and chassis parts, Terrill Machine for engine parts. Good service and price seems better. Also, phoned PlyDo way back when he first started and didn't like his attitude. Just my .02 Jim
I sell P-15 parts (mostly restored stainless and potmetal trim) and know a lot of other vendors who also sell Plymouth stuff. Email me and I will share what I know.