Bob Welch of Hailey, ID sent me these photos of a dog box he has recently completed. Starting with a 'blank' ARE fiberglass shell and a pile of sheet aluminum, he crafted a very good looking and utilitarian topper for his F150.
Since I am in the hunt for a 'newish' Ford F250/350 7.3L turbodiesel truck, I have been quizzing Bob for more information. Hopefully he will forward some diagrams or sketches along with some construction details.
BTW, the "pod" on the top of the camper is a pop-up roof top camper, complete with 3-1/2" thick mattress and electric light. Bob likes his comfort.
EDIT -- Added the photo of the rear view with the tailgate open. Lots of possibilities for this design... water tank, full drawer system, aux battery, pop-up remote control roof vent...