Steve Wilkerson (and maybe others) don't use the part numbers in the Orange Parts book. I sent Wilkenson Pantera a list of the parts I needed for repair of my uprights (with the P/Ns taken from the Ford Orange Book), and he sent me an email back telling me the part numbers were no good, and go to his website to get "the right numbers".
So I bought what I needed from somebody else. It was a pretty standard set of stuff.
The Orange Book is still useful for the drawings and part names.