As Bear implies, that may not the same type of box in the two pics. The one in the drawing is a full width stowage box mounted on the TOP of the rear deck. Although it is not shown in the illustration, there are usually two or four L brackets, or a low rack, welded to the deck to support the box. In the photo, the smaller box is supported by a bracket welded to the REAR of the engine deck. Unfortunately most photos are either unclear, or the tank is cluttered up with extra stowage so the exact bracket configuration is obscured.