Do it like Wil-Mac:
Gurgel had a space frame, the Scamp had a simple 2x4" rectangular tube frame connecting the VW front beam and rear torsion housing. Probably not much more than two straight rails.
The Jeep in a box would come with the military two-piece 16" wheels. They are 5 on 5.5" (140mm) bolt circle. Adapters would let you use them with VW/s 4x130 or 5x205.
Then you'd need a teardrop:
