Is It A Cracked Plate, Scratched Plate Or Just Smudges

Saw an unusual looking 2 cent Jackson and it seemed to have a dark shading where none should be. So I thought I'd bring it up here and see what you think. Is it a cracked plate or scratched plate. New one on me.

1. Consider where the cancel falls.
2. Consider where the cancel should fall based upon the dimensions of the left portion of the cancel on the cover and consider the dimensions of the right portion of the cancel on the stamp.
3. Consider the stamp did not originate on that cover and is a replacement.

1..2..3 strikes how dumb I was about this one. I can't for the life of me figure why someone would make a fake one. I totally thank you for some education. Where would be a good place to send it too for studying. I got it from a dealer on ebay quite a while ago.

Sorry, but I see a genuine cancel here. Philadelphia used abbreviations for itself in cancels, and I believe this reads PHILADA with the last "A" superscripted, followed by PA. It might be just PHILADA PA. The bottom reads (POST OFF)ICE. Compare with this cover being sold by one of our members. The salient part is also lightly struck, but you can tell by the spacing of POST OFFICE with the rest that it is the same cancel that you have:

Also note that both envelopes are addressed "Philada".

As for the other part, is this what you mean by cracked or scratched plate?:

Hard to tell what this is from here. But if the grayer spots are gouges or abrasions, then it would be just incidental damage and not a plate flaw. Take a look with a good magnifier or blow up your image further.

Thank you hy-brasil for the information. The description and explanation you provide makes it a tangible argument for other Philda cancelations. As far as the crack goes it was on the right side of lower lip and appeared to look like a gripper mark. I sincerely appreciate the input from all.

If you examine the left side of the cancel which is on the cover, note where the outer ring is coming on to the stamp. I see it as the right side of the "O" in "POSTAGE." Now look at the cancel on the stamp and where the outer circle is leaving the stamp. I see it leaving the stamp between the "S" and "T" of "POSTAGE." Additionally the circle of the outer ring of the cancel should be circular but it is stretched out to the right due to the two different cancels one on the cover and one on the stamp. Stamp added but both cancels are legitimate for the parts that they show.

As to the line to the left of the nose, I saw that too, but it was not consistent with the "a dark shading where none should be" question in the OP. As confirmed by the OP's later comment, he was looking to the right side of the mouth.