I have an original Mark IV A/C under dash unit I picked up years ago at a yard sale if I remember correct. Seems it's complete with a nice chrome face. Don't have much knowledge about them but am interested in maybe putting it in my 57 2 door sedan. Seems the Vintage Air Co. bought the rights to them and are reproducing them now? Thinking l would like to place it more towards the passenger side so will not interfere with the 4 speed shifter and the usual 3 gauge under dash set up I have. Using the Mr. Gasket "deep throw" shifter for the bench seat tri-fives. Thinking of using a Sanden compressor and have a have a working '57 Deluxe heater original to the car. Would like to hear from anyone who has such a set up in their tri-five along with any tips or info for such a system. Thanks to all who reply.