Tried jumping the starter relay with a screwdriver. Same "click" at the starter. Which tells me ignition switch & trans NSS is OK (?).

Smacked the starter motor with a rubber mallet. Same "click" at the starter.

Starter motor connections appear to be tight as I cannot move/wiggle them (2 separate lugs, not the molded connection pair, when I made new battery/starter cables).

It is an original style (big) starter. I do have another newer style starter from a 90s RAM/Van/Dakota but will have to wait to swap (30* outside and I'm allergic to the cold weather).

Any other suggestions/ideas?