Mogman, what does WFO mean?That regulator was going bad before you even noticed it, the voltage was spiking up very high while you were driving it and using the brakes/turn signals, that is WHY you lost multiple bulbs, There can be no doubt about that, nothing weird about it just the normal way a 60A alternator fails.
Something fails and causes the transistor controlling the field to go intermittently WFO until the field current gets so high it eventually fries the circuit board and looks like this.
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