Just to add to what Bill posted above, I had to replace part of the heater control panel in my Cameo, which has the deluxe heater, many years ago and was able to use the parts from a control unit from a 55 Chev car. I can't remember whether the unit interchanges completely, but the guts were identical.
Bob


55 Cameo 396 TH 400 with overdrive
65 Caliente conv
67 BB Caliente conv
67 Mercury 1 Ton
76 GMC 3/4 ton 454ci
84 Buick Turbo Regal