Go to a local parts store, preferably an older established store, and if they still have the paper parts catalogs, look up their Wagner Brake Hardware Illustrated catalog. It has full size pics of numerous brake shoe return springs to compare your spring with. You might come up with a match or something really close to work with. If nothing local, go to Ebay and search Wagner Brake Catalog. My copy is HU860 from Oct, 1977.
Thank you for the response Don. Unfortunately I have already pursued that path. We have a parts store here in town that has the Wagner catalog, Unfortunately the ones that matched up have been discontinued. Charlie also called all his suppliers and came up with nothing. I do have new ones that are about 3/8" to short. I am considering making clips that would make up the difference and see if that will work.
I don't get my wheels back until the end of May at the earliest, so I figured I would keep looking until I am closer to that time, then resort to plan B.
I did think it was odd that both front and rear springs were broken on the passenger side when I removed the wheels to send off for new spokes. The driver side springs are still in usable condition.