Eureka! Old alt tested bad, replaced it with one that I really didn’t test - system did not charge.
Put a new rebuilt AC-Delco alt on, it tested fine, but no charging. Regulator tested bad. Replaced it and I now have a functional charging system.
Pulled the cover on the bad regulator. If you squint real good you can see the burned wire (non insulated and gray). I guess the hot, rust filled water that did the alternator in killed the regulator as well
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