So, you need an enclosed utility trailer, but all you have is a non-operable old Dodge van? Why not do what a guy in Ithaca did (except the 1:1 was a fullsize GM van)? That's right- cut away the front 1/3 or so, wall off the front portion, and add a tounge!
I built this a couple of years ago, using the rear part of the body and interior tub from an MPC 1980 'Wanted Van' annual kit, the springs and tounge from a Model King Camper, and some spares box wheels and tires.