On the Russ Tandem--pre-war,I have found a partial tube stamp.It's in the shape of a Diamond<>.The center was filed out when the lugs were filed down so any letters are missing.Has anyone seen a stamp like this?Also beside the Diamond is the numbers 19-22.The Russ ad. that Mick sent said that Russ Tandems were made with High Manganese butted tubes,so the stamp and numbers may indicate this---any thoughts?(has chater lea lugs ,headset,and BBs)
sam lingo,pleasanton tx