Update. In case anyone else needs this information - I think I've got it figured out. My husband measured the old ring with a dial caliper. The closest match was a ring size 15-287. Although it is a bobbin winder ring, the models that are shown to fit did not include my machine. We went ahead and ordered 2 rings for $5.00 from Amazon. IT WORKS!!! Hope this helps someone as it was a real big challenge for us to get this figured out. Yes, I have ordered 10 more rings - I should be set for years to come!