New alternator, not charging

Assuming your wiring is correct for a 65, you have a 1 field wire voltage regulator.
It should look like this.

Screenshot_20220215-222807.png

Your alternator origionally would have looked like this.

Screenshot_20220215-223045.png

The parts store replacement would have looked like this (most likely). Note the connector (blue arrow) is cut off. It is grounded to the frame of the alternator.

Screenshot_20220215-223357.png

If you were given an alternator that looks like this ( note both connectors are intact)
You might have the wrong alternator

Screenshot_20220215-223712.png

With an ohm meter you can test to see if the alternator you were given was an isolated field (2 field wires) or non isolated field (1 field wire) alternator

My bet though is the catastrophic failure of the alternator killed the voltage regulator