Hey Brad, your third card is another 1936 blue.
I just checked all my 36-37 for the location of the stamp, all 17 1936 that I have are centered, I have 4 37 that are not centered but 14 more that are centered. The 4 that are not centered are like yours with the stamp to the left. Looks to be some kind of printing variation. Here is one of mine-
