Low Grade 1847 N-23 Large Cent With Unique 7?

I can't see enough detail to agree or disagree on the variety. There were lots of date overpunches in 1847. Any chance that's a clue regarding the 7?

I have taken another set of photos which, I think, are clearer than my previous set of detail photos. Seems I am still trying to figure out this photography thing!

These should be adequate enough should anyone want to verify my attribution and also show more detail of the 7 in question.

Thank you Conder101. I did not know about the later use with N-11 (I should have known if I had read more carefully). That seems to me to be an argument against die crumbling. I wonder what else could account for the 7 appearing the way it does? I have searched through examples of N-23 and now N-11, and cannot find another example of a 7 which appears like this. I am afraid that I do not know if only one Obverse die was used for N-23 and N-11 or would there have been multiple dies? Were date numbers punched individually with large cents?

Corrosion can actually "move" devices as to distort them.
I can't make a determination about the 7.

Through 1939 they were individually punched, in 1840 they experimented with two digit punches, 1841 on are 4 digit logotype punches.