No Ray, the pickup rear fenders have a 90* flange that bolts to the side of the PU box. Panel/Sub/Canopy rear fenders don't have a flange and bolt up into the wheel opening much the same as a Chev. car fender does.
#599122 is a '39-'46 1/2-ton and 3/4-ton panel right rear fender if I remember right. I hope you aren't looking for '39 PU rear fenders, they are a little difficult to find in good shape.
