there are rebuilt A/C servos available for $300 for that car. The engine driven vacuum pump has to work also (to work the door locks, engine shut off, and all the other HVAC damper doors.

That system is EXTREMELY costly and difficult to restore to good working condition if in poor condition now. All the vacuum ;motors' on the heaver/ac box will need checking and probably replacing, the servo controller, and of course the refrigerant system itself. The 'servo' switched the doors and modulateds the amount of hot water going through the heater core to control the temp.