I have a question. Ì have (and have seen) some vintage knives with the wenger-claw-style can opener (1946 - 1951) and with the backside philipps screwdriver (1952 - today) or the fishscaler (1952 - today). They all look original with all the vintage look and tools. But compared with the data sheet and common knowledge, that could not be possible, because the wenger style can opener disappeared before the philips and fish scaler started. So what do you think is correct? I`m pretty sure about the data for the new +pat can opener (1951 - 1971) and I see no reason why they should have used the older one after 1951. So could it be that the start of the philips and fish scaler was not in 1952 but before, 1951 or 1950? What do you think? Has anybody also some knives with this tool combination?