[dsraven]

if you have a plan as to what you want, but dont have the metalworking tools to match the plan, you could make a 2 sided form out of MDF with routered in details. then use a light gauge of sheet, for ease of bending. place the oversized sheet into the form and then squeeze the form together in a vice or use threaded rod etc to press the form together. if you were making somethinglike LeeGreens shape the sides could be added after the main form was made as they would be wrinkled in a form due to the amount of shrinking needed. just leave a small overhang out of the sides of the form and then hammer form them around the outside of the wooden form. I seem to remember a video that japhands (make it custom) did using this method to build the floor of a battery box or something like that.
I have made stake pockets before using a U shaped piece of formed sheet, then cut out the corners where it needed to bend along a long curve, made the curve shape required on the side pieces, pushed a piece of wood inside the formed part to help keep the shape and dimension the same, then tacked the central "flap" back along the curved part and tacked it on both sides as i pushed it together against the wooden backer.some tape also helps to keep the parts held tight and square but the part needs to be kept cool as you tack so the tape glue doesn't go gooey and also so the part doesn't warp. they would be different than what you want, likely, as the outside edges were smooth, not with a detail, and the corners were square. where there is a will there is a way to make it happen though.