Thanks for the tips!
DeniseM, I'm familiar with Little Stitches in Missouri City. Is that the one you mean? I didn't know they worked on vintage machines. They have done warranty service on a new machine I have, and they are good, but an hour drive away from me. Also, professional repairs would cost a lot more than I paid for the machine, which makes me think I need to figure out how to do whatever it needs before I go that route.
Mark, the tops of the switches are broken off, but they do work pretty easily with a thumbnail. I've tried the motor in both positions, and there isn't the slightest hum coming from it. From the look of all that black gunk that spewed from it at one time, it seems fairly likely the motor burned out. Thanks for the link to the Yahoo group. I've put in my application to join.