Hi I came across this 1957 what I believe to be a double can anyone help me out with what I may have found Many Thanks
Not a RPM. Notice the top of the apparent inner D is not close to the same size as the top of the outer D, so the MM is also MD. A normal RPM at that time was usually 2 blows to the same punch to set it. If done accurately, it is seen as just one. If off, a RPM, but the punch is the same size and font. Jim