Well, true to their word, the good folks at APQS called me back. I'd pulled that shaft hard enough to pull the bushing out of place! Yesterday (after some tactful coaching) I carefully tapped the bushing back into place with the help of some Loc-tite to keep it there. Today, once the Loc-tite had cured enough, I buffed the shaft, replaced the hook assembly and timed the machine. Whoo hoo! It's all back together now, and working fine, so far. I've even put a rather picky little thread on the machine for my tester, and it's running beautifully. There is a chance that the machine hasn't been this nicely timed since it was new.
Another thing that I did the other day is repack the gear grease - that has made the machine MUCH quieter! I'd write more, but I'm dying to get stitching again. I've got a little quilt on that I made at least a year ago - once I know nothing is going to suddenly go wrong, I'll put the next customer quilt on the machine.
It was worth it, becuase the new foot is so much easier to use with templates and rulers (something that I've never mastered the way I wanted to). I've already been playing with some of the cool templates that I've collected over the years and it's so much fun!!