A '39 PU rear fender looks just like a '40-'46 PU rear fender from a side view, except for being 1-3/8" wider. If you lay the fenders on the floor, or measure from the box side to the wheel opening, the '39 fenders will be about 13" wide, and the '40-'46 about 11-1/2" wide. This is measured at the top of the wheel opening.
