I think I've got it sewing now. Today I went back to the start of everything I had done--redid every step from cleaning bobbin case to removing top cover. Didn't find anything I could see but when I put everything back together it sews. Actually this is remarkable because I now remember I packed this machine away about 10 years ago because it stopped sewing anything but simple straight stitch. I guess it was tired and had long enough nap. Thanks for all the suggestions and now I get to play with my new old toy.