Do we tave an air conditionning unit that would replace the OEM unit on a 1968?
I don't think I can repair the original unit as several parts are missing...

 

you can replace a missing or non‑repairable OEM air conditioning unit on a 1968 car with a modern aftermarket system instead of trying to fix whatever is left of the original. There are companies like Classic Auto Air and Vintage Air that make complete retrofit A/C kits engineered to fit classic vehicles, including ’68 models for pretty much every classic line (Chevelle, Camaro, Mustang, Firebird, etc.). These kits include a new evaporator, condenser, compressor, hoses and controls designed to fit your car with minimal modification and will give you modern cooling performance. They often use fully electronic controls and simplified wiring so you don’t have to source individual parts yourself. There are also universal under‑dash or custom kits https://tropical-casino.com/ if you want something that works in a variety of cars rather than model‑specific gear