I really like this coin, and I also think it has potential to be a 65. Seeing that it isn't attributed as a "Mint Error - Planchet Crack", and I would like to have that noted on the slab, if it was your coin, would you try and cross it at PCGS (Minimum 64 w/attribution), send it to NGC for reconsideration and attribution, or just leave it as it is? I figure there would be a price jump if it did make 65, but even just having the error attributed with move the value up a bit (enough to offset submission costs at least).
I thought the same thing, especially the rim bruise on the reverse at 2 o'clock. Looks like metal from the rim has been pushed into the field. I would think the grader would know enough about coins to recognize if that were the case. So I must assume it is some sort of planchet anomaly that extends from the "I" in Missouri clear past the "T" in centennial, likely the result of a lamination that lowered the surface of the rim for a few millimeters thereby creating an optical illusion of the rim being pushed into the field.