2 questions!

You can diagnose your white switch box pretty easily. Unplug the master vacuum plug and identify where vacuum comes in when your idling. If you don't have vacuum to the plug, you know you have a leak. I had a Mighty-Vac set with the tubing and fitting kit at the time and was able to connect it to each actuator to operate them. You could do the same thing with a piece of washer tubing with some fittings on it and jump from the engine vacuum port to each actuator across the plug. Here's the replacement unit.
OER 3895790: AC/Heater Control Switch 1960-1974 Mopar A/B/E-Body - JEGS High Performance