Thanks for the input Greg. The engine side of the A/C heater box is long gone and a plate is now covering the hole in the firewall. I was going to purchase one of these to replace the missing housing. One issue that came up was whether it's possible to replace the dash controls from A/C to non A/C.
Yes NH looks to see if you have a working defroster. I've got everything else functional except that part of the car and it's way frustrating not being able to drive it now.
Say hello to my leetle friend..Presenting the "FIRETOAD"