Have any of you checked online to find the belts you need? Of course you should check with your Singer dealer, too. One other idea is to go to an old (and old-fashioned) hardware store. They used to carry sewing machine parts and some still have parts for the older machines. There's one in Opelousas that has just the biggest mix of things for the home. I've gotten all sorts of replacement parts for things like the meat grinder, pressure cooker, window hardware, etc. If nothing else, they may be able to tell you where you can find the item. They've been in business since 1878! Imagine that.
Here's the info in case you want to contact them:
J.B. Sandoz Store
312 North Main Street
Opelousas, LA 70570
337-942-3564