The truck may have been sold as a cab and chassis, and a dealer or first purchaser put the bed on. If the sides were torched out, it probably wasn't a dealer. They probably didn't get the bed blocked up high enough to clear the duals and decided to chop it out instead of doing it right.
Shoot a PM to user "MPandC" on here. He could probably fab something up to match your bed edges, or at least patch pieces with the beading on them. Robert is a metal artist. You can check out some of his stuff
HERE. I don't know if he'd be willing to take on your project, but it can't hurt to ask.
