here is the starting of mine.
here is welded in
I dont have any pics of the back. But there is three pieces of tubing behind it. A 1x2 at the top and 1x1 at the body line and the bottom. They are spot welded to the skin, and the bottom one is .120 think and has bracing runing to the bottom of the bed to help the rollpan from collapsing if something happens like the wrong switch gets hit. I will take some more pics when i get a chance