That 2nd one is a gold mine. I found my mini-truck fiberglass for about $400. Since then, have been searching for a buddy. Not many fiberglass one out there. If the forward compartment goes all the way thru from left to right (rather than a full bed), someone should really get it. Thats prime area (after some mods) for storing the 'stuff' you usually put in rear of car.
The one thing I'd suggest confirming is the width. Some utility beds actually exceeded the width of the truck doors (side to side), and when you make a trailer out of them they are too wide to track anything other than a full-size vehicle - IMO. This one does not appear to be the wide body.