That would explain why I don't see them.I normally don't go on Ebay.I try to stay away from that place.But I'll have to go look and see what they go for.
@junkman , I checked mine this morning, and there are no markings at all on the heat drum. Mine was made by Coleman and shipped to a store in Minneapolis in February, 1963, if I am reading the date code on the box correctly. Great addition to a good 502! Take care, and God Bless! Every Good Wish, Doc