Charging problems

You likely got screwed by the rebuilt you bought. The difference between 69, and 70 and later is that 70/ later has TWO field connections. Lots of these rebuilds have one brush grounded to work on 69/ earlier.

Unhook both brush / field wires. Check continuity to ground from each. There should be NONE

The VR must be grounded.

Once you get the car running, get the engine idle adjusted up to "fast idle" to get an ammeter reading. This shows you have not burnt anything up.
Next unhook one alternator field wire one at a time. Each time should cause the thing to stop charging.

Unhook the VR. Again it should "not charge."

If all this is OK you likely have a bad VR