I actually found a SM repairman who makes house calls. He came yesterday, worked my Singer 15-19 completely over, serviced it, even a new needle, fixed the problem (the feed dogs were way "off", causing puckering in the underneath seam). Even a new thread-cutter, mine was broken.
It just purrs like a kitten now and sews beautifully.
This man was just a delight and since I am a relatively new sewer and didn't know much about the machine, he was a *lot* of help. He charged me $65, which I thought was great, especially since he was here well over an hour.
Sherry