This coin has been setting around for years and I thought Id look at it again and see what some of you thought.
It looks regular to me. I am basing that opinion off these images: http://www.lincolncentresource.com/Featured/1946Sinverted.html
I think it could be. The typical upper end is teardrop shaped not flat-ended like yours. Also, on the normal orientation, the upper teardrop is barely connected to the rest of the "S" (and often disconnected). That is more like the bottom of your coin. Finally, the upper loop on the typical mint mark has a more angular shape to it (almost sort of triangular). The more angular loop is on the bottom on yours. Unfortunately, it has absorbed some damage and thus may not be clean enough to absolutely know for sure. It may simply be the trumpet tail "S" with some damage.
Well it looked interesting so I thought I take a shot and post it. I have others that I need to look at from when I put them away years ago. I thank you al for the comments. Ed