Okay, I really want this one to be real, but my best guess is it's just worn down either from major handling or because someone filed it down.
http://img.photobucket.com/albums/v...le-sided.jpgI cannot see anything on the back that would indicate why the tail side is blank, but you can make out a bit of the "N" in the upper middle, so my guess is it's just worn.
I still thought it was an intersting penny nonetheless.
