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.

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