Trying to perfectly match a reflector on an old Ross is a pretty entertaining exercise IMHO but if you simply take the time to look at your existing rear reflector, noting the brand and model, you can then narrow your search and find the exact one you are looking for. The bracket should not be hard to match, it was one of a few common types. Someone in a early reply suggested going to a local co-op (great suggestion) they will have piles of old reflectors to choose from.