We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "Fred" saying
something like:

I would have thought the AVR would have terminals for a battery for the
initial excitation? Given that this is a 1980's alternator I doubt the
electronics at the time would have stretched to supplying 71V and 18A. I
may well be wrong but I would have thought a mechanical vibrating regulator
would be more likely.

I was building those into gensets in the early 80s, and yes, they were
self-exciting. Mechanical vibrators are so 50s, daddy-oh.