I think you're correct, although it's still not a complete fix.

I had two spare boxes, (as well as a second one on the passenger firewall that services some accessories). Anyway, I found the spare box with the tightest connectors, and drilled out the bad rivet (#1 of course). Then cleaned up the surfaces, and reattached them with a copper rivet (I didn't have any small brass nuts for my small brass bolts). I made sure that everything was tight as possible and switched it out with my primary (3-4 loose connector) fusebox.

It seems to have really helped. The only thing that brings on the amp glow now is my rather loud old-style blower fan. All other subsystems appear good and do not drag the voltimeter reading down more than 2 volts (~12 volts on low end)

For some reason, I got my dashboard lights back in the bargain.

Thanks for the info and advice.