Here's the update you've all been waiting for. I swung by my favorite LBS after work today. I asked the old man behind the counter if the fork could be reamed from 21.1 to 22.2mm. After complimenting the nice fork crown, he said he could and has done the job many times--including on old Schwinn steerer tubes. On top of that, he has never heard of one failing afterwards.
I'll let you know what happens in about a week after he's done with mine.