Here is position 72 - One that I find most difficult to positively identify, due to the less visible weak frameline to the left...with no obvious other markings, beside the pos dot in the left oval.
Last from 2nd column is 92. The key feature is the large Dot in the bottom margin below the 7.
That shows that sometimes, off-center stamps may provide good clue for identification. (in this case, large bottom margin is preferable, while for top row, large top margins provide most of the needed clues.
If you have actual copy of any of those (12, 22,32,72 or 92, please feel free to Post them here.