I found one and bought it, truck and all ... for a couple hundred. I cannot remember if it is a 16ft or 20ft bed though. Were you looking for a horse drawn spreader? I have three of those.
I think you asked the wrong person about buying equipment! ;o) Cav likes to buy rusting old relics and drags them to his farm to finish rusting down. Hair keeps kidding him about his truck "planters".