Well, there you go.
DarkMinion, I did retighten good and hard (by hand, no air), then loosened again, then used the air hammer again, and, whaddayaknow, off it came!
Ironman, Thank you for the suggestions, but fortunately, I got it without resorting to a new construction project.
As for the taper, sorry to be disagreeable, but there is definitely a taper.
I've indicated it in the photos below:
Bottom Side of Steering Wheel
- Eric