That's not the best of starting points...
Every Twonk says that....! But riddle me this, if it's just for economy, why didn't they sell the vehicle as a 4qwd, and instead buy a peugeot 206 or BMW 320 e46 diesel? And where is the original prop? Why did they dispose of it? Could it be because the VCU was cooked and they yanked it when it started damaging the other driveline components but fore before it totallty killed them?
I hate to be that guy but it's 50/50 if this is going to be scrap metal that's going to further wreck your 4wd system, or a good serviceable component that's going to resurrect your vehicle.
Pending better advice from "the grown-ups", I'd get under the car, and
OPEN the IRD (Transfer Box) filler port first, then once you know its opening, drain the IRD oil and see what it's like, remembering that all that glitters is not gold, and in the case of oil glitter couldn't be any further from gold even if we had 386 elements in the periodic table. The reason Is stressed opening the filler plug first is they have a tendency to stick, and a couple of guys have been marooned when they drained the IRD oil for a service and couldn't get the filler plug open to refill their now empty IRD.
The very fact your vehicle has had its prop removed "for economy" ah, ah! AHH!! PULL-CHIT!!! - sorry about that sneeze, but something triggered my allergies there... As I've alluded to elsewhere in this thread, removing the prop and VCU suggests your transmission components have been exposed to a tight/seized IRD, and as such the rear diff and IRD will be more
"delicate" than other examples might be. Ergo you really ought to do a "one wheel up" test when you fit your new propshaft, refer to a sticky thread in this section
"tests every new Freelander driver should to their vehicle" for what's involved.
Do this dest and check out the results BEFORE driving with the prop - as you really know naff all about the new prop other than the seller's word, so a one wheel up test will prove the new VCU is good before you run the vvehicle and do irreprerable damage to your IRD and or diff.