Musing on converting two Range Rovers into one?

Well, this might be one of my more lunatic ideas, but here goes! I have two two-door Range Rovers, both the same colour. One is an early tax-exempt model with a good Isuzu 2.8TD engine that pulls well and returns over

30mpg., It has a good LT95 box and overdrive. The body is ok, but both door bottoms are badly corroded and the window regulators have rusted away, as have the rear window glazing strips. It also needs a fair bit of welding around the sills and the rear cross-member. The other one is a later two door V8. It has the 9.35CR engine coupled to a whiny LT95 gearbox with a sloppy gearchange, but it does have the higher ratio transfer box that came with the 9.35CR engines, so there is no overdrive. This later one has a good body (doors ok, and the later type of sliding rear windows that are rot-free). It also has a good interior and headlining, and working factory aircon. The V8 engine is basically good, and has had a recent new camshaft and top-end overhaul. However, it is still not running right (I think the Stromberg carburettors are in need of a rebuild or replacing with something different). My question is how complicated would it be build one good Range Rover out of the two? Is it a practical proposition to swap the bodies so that I end up using the 1972 chassis, engine and gearbox but with the later body, bulkhead, good interior and headlining and aircon? I'd obviously have to sort out the welding to the rear of the 1972 chassis but assume that would be straightforward with the body off? Or is it more sensible just to swap the engines and gearboxes, so I end up keeping the later model, and live with paying ever-increasing road tax each year? If I were to use the later chassis with the engine and gearbox from the earlier car, I think I would like to lose the overdrive and change to the higher ratio transfer box, which should match with the Isuzu power/torque curve much better. How easy would it be to modify the LT95 out of the earlier car to the higher ratio transfer box? Or would it be better to rebuild the gearbox that is already in the later car? All ideas and suggestions welcome! And for another possibly lunatic idea, also part of my Land Rover fleet reduction plan, please see my following post. Thanks in advance. Simon.