I have made a bed for a 37 chevy had a metal shop bend the metal in a 8ft break bend and for the top on the sides for the roll i took a piece of tubing........plasma cut it the intire length slid it onto the bed side and mig welded it on. It was alot easier than trying to keep it straight while welding it by being plasma cut and slid on to the top. You would nee to see if you can get metal bent and plasma cut and it will make it alot easier to build
