Welcome. Yes as said there is a Trading Post, but not sure if there is a minimum post count to list there. Maybe it is ten posts?
Your best bet is I have to say Ebay, GB and calling all the Used parts dealers. Such as Jack First, Hoosier, Popperts, Dick Williams. Best bet would be give Lee a call at Lees Gun Parts though. They are in Texas and have alot of stuff. Quite a few others too that are slipping my mind right now. Good Luck.