Sorry, I was being a "smartie" about the "what little value there was" then realized that it still would be a large cent and at least interesting. My apologies.
It's also possible that the mark is from being hit by the digging tool. I've done this a few times over the years. Thank goodness, most were just common date silver coins except for one, a 1895-S Barber half dollar in XF condition. Hit it with my digging tool right across the face of the coin. Unfortunately, I was in a place that I had to dig as small a hole as possible to remove the targets.
That's a cool find, Carson, but has little value as a counterstamp. It just looks like random letters applied to the coin for no apparent reason. There's a slight possibility that the "X C" could stand for ten cents "revaluing" the coin for some purpose. It was done occasionally. More likely though, it was just done by someone testing a punch or who had nothing better to do. Bruce