Cranks but won't start. Unplug ground at field spade on Alternator and it starts?

It would be better to replace those terminals. Some of the supply sources have changed/ dried up so you will have to search. "Packard 56" and various. Be CAREFUL that the terminal has the tension area wrapped around the sides as exactly in your photo. There are some different ones that bend over the top and they will not fit some Mopar connector shells

I know Mattox has done some posts on this.

The other thing is, if you get this finally settled down, working, but still have some voltage drop in the IGN1 "run" circuit, that will cause overcharging as the VR sense will be low

One way around that is to electrically break the "run" IGN1 coming out into the bay, use the end from the switch to fire a relay, and supply the relay contact power from say, the starter relay big stud, and then put all the underhood "run" loads on the switched contact.