Re: Iver Johnson .22
the only time iver johnson's arms & cycle works used the "H" letter code on a 22 rimfire revolver was in the late 1950s and 1960s. it was used on the late production model 55 and the model 55A. i do not have an official serial number list for this model. the model 55 was manufactured between march 1955 and 1960, the model 55A was manufatured between 1961 and 1978. A low "H" letter code number is most likely going to be 1958/59.