Reverse looks like it was gripped with pliers to hold onto it while the other side was ground down. Someone playing games.
I don't think it is a grinding wheel because the surface is not fresh and the edges are turned up. Nevertheless, your coin is damaged. Spend it. I changed my mind. Don't spend it. It is probably man made damage but it is better to keep searching for an answer. This one cannot be done for 100% certainty with images.
