Techs are great razors. So far I have a post war gold plated NDC ball end, a gold plated contract ball end and a Z3 ball end. I’m wanting to find a couple each of a Z1, Z2 and Z4 ball end techs and another Z3 ball end in good shape. I think it would be nice to have a complete set from a particular year. One set in nickel and the other in gold