That is a great pic, but a truck of that vintage should only be hauling proper bales! Oh the ignominy of round balers!! ;-P
My '49 has short stakes in the stake pockets and I just hang 3/8" plywood from those down the sides and across the front. A couple screws each side does the trick and a sheet on the floor. I've hauled concrete and all sorts of rough stuff with nary an (extra) scratch.
