I inherited a very old Sears Roebuck Craftsman metal case electric belt sander. It still works. It appears to take a 3"x 28" belt. Are these belts availabe ANYWHERE? The model number of the sander is: 207.2230. I searched the Sears Parts Store website and found nothing.
I just rebuilt the same model, bought at a garage sale with a case for $4. It is a genuine find, built like a tank.
I located a source for belts, and have some on order. Try talking to Roy at sandpaper.ca, located in Ontario. He will special order what you need. There is a minumum order quantity, but his prices are lower than comparable stuff in hardware stores.