"I have no reason to believe it is not the original wiring loom."
The loom will not change only the dynamo, regulator and battery polarity. Series D's were +ve earth, often when fitting Lucas dynamos and regs to B or C's the polarity was changed. I think the early JG units were +ve also.
The loom will not change only the dynamo, regulator and battery polarity. Series D's were +ve earth, often when fitting Lucas dynamos and regs to B or C's the polarity was changed. I think the early JG units were +ve also.