Hey Don:
This is Emmett from McComb. I met you at the NO show.
I'm putting together the 57 TR3.
Anyways, I tried to repair my control head, only to finally realise that all of the small parts weren't there. I gave up and bought a complete new head.
I have many control head parts, including a new wire harness, and button assembly if you could use them.
The article you are hunting is in the wiki section.
Good luck, Emmett