I hope I don't lead you down the wrong path but when I put a new regulator on the 38 the fellow I bought it from adjusted the voltage it puts out to just over 8 volts max. I am NOT an electrics expert but from what he said it would not be surprising to me if the only difference in 6V & 12V regulators is the adjustment. This guy rebuilds starters, generators, etc. so he should know what he's talking about.

Save a life, adopt a senior shelter pet.
The three main causes of blindness: Cataracts, Politics, Religion.
Name your dog Naked so you can walk Naked in the park.