with the battery being cycled to death a number of times, it will be low on reserve amps. May wanna get that load tested at O'reillys or somewhere they can put a carbon pile on it. Old friend said every time a car battery goes dead, it loses 7% of its storage capacity. If those resistor coils ohm out (continuity between ends) they my still be good. remove the top and take some fine sandpaper or a points file and gently clean the contacts of the points in the VR. They may have a little bump one one side and a pit on the other while your waiting for the new VR. Now you can chase that vacuum leak. My guess is the heater control valve if it has a vacuum port or heater switch. some were vacuum assisted but maybe only on the higher lines. start pinching lines off from the manifold with a pair of pliers and listen for an idle change. then chase that hose to your leak.
