.I have been thinking about this...
Making a flat bed/goosneck bed from scratch wouldn't b e that difficult....hardest part would be getting the framing behind the cab of the pickup just right...otherwise, it's a fairly straight foreward deal...
If you are talking about a box back...like plumbers and electricians use...that would be a bit more difficult...but almost all of it are straight lines...measure twice, cut once...
Or just a work box that sits in the bed...same deal...just on a smaller scale...plastic would be easier...cause I don't knwo if they make diamond plate THAT small...LOL...
Then again...I'm fairly n ew to modeling...I may be talking out my yoohoo here...