Blowing voltage regulators

But you still have a single field alternator.
Not really.
What you have the exact same alternator with positive controlling regulation instead of ground controlling regulation.
In the US its called 'A' Circuit vs. 'B' circuit. In the UK to quote BC_Johnny on Speedtalk "I know it as 'field to positive' and 'field to negative' switching, whether the reg is interposed between the positive feed or negative ground." That's a lot clearer description.