I finally got my dash apart and got the old busted up plastic vacuum controls out of my 71. I was pleased to find that the part is still available from the dealer. It did take a little leg work to track it down, so I wanted to share this with anyone else that needs it.
The new part number is 3895790 and it was $61.35.
Interesting note, the part appears to have been made in 2000, and is identical to the one in my 69 Fury Convertible.
I have heat and air now!!