This does indeed have quite a rack! 
And now, it has a bed too:
Sorry the images are hurting a bit because of low lighting. Nonetheless, here they are.
The bed is close to being done:
And as is often the case, there is more to this than a sheet of evergreen. The bed tapers toward the front, and in that area will be wood deck fill, and what’s hard to see is a trough for wire cable in the center, which drops down and opens again in the rear. And a few “D” rings. The rear has a full width bed roller and fairly elaborate sides.
Toward the middle are two hydraulically activated risers - which are evidently used for leverage, and balance when loading. These use brass brackets, remnant kit parts, old sprue, and evergreen - perfect. Alas, I never did all that well with physics, so I won’t over-postulate on the roll of these mid deck rollers! The picture above has two sets of these rollers - rear and mid - and, no, I don’t know why??? The type I’m using are based on some I saw on Western Start 8x8 truck - beyond that… 
who knows?
So here we are - thanks for having a look and happy model building,
Cheers
Nick