> ...where they stand
> in the world of vehicles - that is something really unique

Only in that they are rear-engined large vans. There are plenty of other
medium & large 4WD vans with offroad capability.

> ...I would tear down the vehicle to bare bones, bead blast the
> entire thing, get rid of all rust, weld in new metal where needed, and
> come back with a powder coated body primer or epoxy primer then apply

Do it right... seam-weld it first; strip-bath the body to get rid of all
rust, including internal, then have a high-quality zinc plating done,
making sure that the solution enters and entirely fills ALL "sealed"
spaces eg sills, pillars etc. Then gold-plate and polish it...?

That's what I'd do if *I* had the money... well, maybe not the
gold-plating.