Quote:
Additionally, your block appears to be perf 11x10.5 which would make it a J85 so please re-check the perforations.
Don, If the block of 4 was a rotary press printing, the horizontal perforations would be aligned vertically between rows. Random perforation alignment can occur on the vertical rows. horizontal rows were perforated by a bar (or drum) perforator that punched holes in horizontal rows all at the same time.
It is often possible to identify a stamp just by carefully examining it. In addition to random alignment of perforation rows, the shorter aspect ratio of the design and the poorly applied local precancel are indicators that the stamps were from a flat plate printing.