That is actually something I hadn't tried yet, so I just did. Unfortunately, with both shift rods disconnected from the column, the shift lever still only moves up/down. It won't budge to move it over and select 1/R.
One other thing to mention: Turning the steering wheel causes the shift lever to move up and down slightly. I suspect that SOMETHING is stuck between the actual steering shaft and the shift components, though I didn't see anything when I partially disassembled it a couple weeks ago. May have to yank the entire column and completely disassemble it.
Thanks for the new ideas!