Got this PC off Ebay. Not used and the back is divided with a one cent stamp box. Seller listed as 1916 but I'm wondering if he was getting this from the "D" which looks a little like the Detroit road uni "D" of 1916. I realize the "D" could be from any local town team or from Dallas, Dayton, Duluth, etc.
Your best guess on the year range of the photo ?