Engine wiring harness question / discussion...

Well yeah, it is, sort of. That wiring still feeds loads throughout the car, and becomes a parallel path. So you still need to make certain the wiring is in good shape, the ammeter terminals are not damaged, the ammeter not damaged or jumpered, and the big red and big lack bulkhead connector terminals have been repaired or replaces.

I'm not sayin' this specifically in your case, just generally

Good points! The ammeter terminals and components are in nice OE condition.