Send it to SGC.
Don't mess with the card. Grade it as is. It is my belief that folks buy N172s for the image on the front not the grade on the flip.
There are folks on this board that know FAR more about N172s than I do and hopefully they will chime in. I own a measly 7 HOFers and there are folks on this board that literally wrote the book on N172s.
http://www.sgccard.com
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