Your dash controls for the heater/ac are a Chrysler product from the 70's. Parts are found at the wrecking lot, or you may try your Chrysler/Dodge dealer. Dodge vans and trucks. The autos of that period used a modified version of same system.
"LOVE and LOSS, are two of the greatest emotions one can experience. -- I went to school to learn about "WHAT GOES UP MUST COME DOWN" but I had to live my life to learn the lesson of: 'WITH LOVE THERE WILL BE SORROW'."
David Stewart. (after loosing my NAVIGATOR)