What really bothers me is the scuffing that makes the grill show clearly and cuts through the cancel.
With all due respect, what you are calling "scuffing" is not evident in the first picture and should be if it was damage to the paper. In view of the original photo the effect you are seeing in the second is most likely an optical effect. Your comments read as if you are starting with the assumption that it is fake until proven otherwise. That's fine, but let's look at the evidence a bit more evenhandedly.
Although I am not able to tell the point shape directly, I do see what appears to be a horizontal half row at the top of the grilling in photo "1." This row is just above the level of the eyes in the portrait. This row surmounts a 16 point column extending down to the letter "O" of "ONE". By this measure it is a 14x16 point array. This point count is correct for an E-grill, and the row of half points at the top is an additional characteristic of E-grills (at top or bottom or both). I have no hesitation in suggesting that this stamp is a number 86, with a rather strongly impressed grill. Bill Crowe and I see it the same way.
Whether it is original to the cover on which it is mounted is a completely separate question, and in view of the lack of surrounding detail one which I am completely unable to address.