Larry, also they sometimes make mistakes and pick up the wrong punch. I had a Thomas Wild hammer pigeon trap gun with nominal bore not marked so it was impossible to say whether it was in proof or not. I sent it off for re-proof to get it clarified. Sometimes in that era you referred to and before the chamber length was sometimes stamped on the forend lump by the maker. Along with Hugh, I have seen this on Greener GP guns. Lagopus.....