Adrian, are you going with the assumption that the die cast lock was in production before the Iron or Brass one's that we have been discussing ? For lack of a known model #, I will refer to these (Brass & Iron ) lock's as the model 10...You know what I mean, the series 10 or H 10 or whatever they were called back then....I have the same die cast lock that you are showing with the U.S. on the reverse side.........Have you been able to date this lock?
...........NICE FIND..............Donnie