Thanks for all the replies! I'll definitely bookmark this thread for future reference.
Lesson learned: Know what you're talking about before you talk about it. The bobbin case that I borrowed from the other old Kenmore "fit" in the sense that it did go in the shuttle, but it still wasn't the right bobbin case. My osmg dug one out of his boney pile, and with the right bobbin in it, it picked up the thread. (Imagine that!
) It's still at the shop for a rewire (I do NOT fool with electricity-everyone has an edge, and there's mine) and a new friction drive rubber.