Ok, so I went home at lunch, gave the Runner one of the batteries from the 80 and she fired right up. Brought the battery to Checker's on the way back to work for a charge & load test, will see what they come up with on my way home. That battery said 2002 on the side, so perhaps today is its day to go to battery heaven.
99 uzj100, gx470
05 525EXC, 01 XT225, 07 TTR90, 07 CRF50