Internal VR?

I met a guy at the last car show with a gorgeous 69 Dart 340/410 that had a Chome Powermaster unit, the regulator as it appeared was mounted externally on the Alternator. He also had a Mopar Blue 69 down constant voltage Regulator on the firewall and both were wired in! I told him this is not right! What gives?

It is a Little hard to see in this pic, but a small external can mounted on top of the alternator.

View attachment 1715755965
So TWO voltage regulators??? I know what a voltage regulator does. I guess it would be OK if it was wired properly, but what would be the point?