well, i know how to do this now and save the knob. you remove the
transmission cap covering the tuning gears. with this out of the
way, there is room to then access the back of the dialknob w/long
shanked thin blade screwdriver. the hole in the faceplate is big
enough to reveal the ports in the back of the dial knob assbly. the
screws holding the black knob to the skirt will appear in little
'windows' as the dial is rotated. remove as they appear until all 3
are out, and black knob will come off. a magnet helps w/retrieval.
you now have access to the front of the shaft.

instead of trying to wiggle or add solvents from the front, i took a
flat tipped punch and very gently tapped on the back of the dial,
which since the transmission cap is off, you can now also see/access.
tapping was on the thick buching part of of the dial, right at the
shaft. knob pops right off. you could work carefully tapping around
the knob base while rotating the shaft i guess, if it was stuck badly.

i think it was stiction holding it -- shaft goo was completely liquid
and there were no dings on the shaft. yet knob wouldn't just slip
off.

ab