Sounds like a fantastic trip! Was it worth hiring the Defender camper?
It WAS a fantastic trip! Absolutely one of the best trips I have ever taken.
As for Defender: our other options were to rent cars, 2WD vans kitted out, 4WD trucks not kitted out, SuperDefenders (google iceland super defender) or other truck/camper combos. We chose the 130 because...well, because Defender. As I am in process of extracting myself from work obligations, it was a good run in this type of rig to see if it is liveable. It is, but we would change a few things.
The Defender could have used heated seats, windscreen (winterkomfortpaket), AC to help with de-misting when we got in with wet clothes, a longer range fuel tank. It did have a Webasto supplementary diesel heater.
Almost 30K kilometers and the stock Continental CrossContact AT tires were getting close on tread depth. These are the factory standard Euro Defender tire. Truck did have the 130 helper springs inside the standard coils, but sagged in the rear due to camper. An air assist would be a nice touch. The water tank held up OK, prob 60L, the camper itself was heated by propane. Inefficient as we ran out at 3am one night, and I froze my self changing tanks! Diesel heat would be nice. Thetford cassette toilet was a cinch, no fuss, no muss.
All in all, a good rig, and a good experience. Especially because the wife enjoyed herself, had the "comforts" she desires, and was warm enough.
With this as a baseline, we discussed the options of a 130 ambulance conversion. They are plentiful over here, and a few different configs available. I would go for a 94 model year, which would give us a 2019 importation date. 94 would get the 300TDi with no electrics to speak of. Add an overdrive and would probably be ok withoutt a 6-speed gearbox.
Most ambulances have a hella big rear overhang. We discussed getting rid of rear doors, replace with a panel, and bob the tail at an angle. Install RV type windows and a door on the side, and it is a good base to build out from.
We probably did 300 kilometers on unpaved roads. From newly graded gravel, to washboard, to tire swallowing pothole after pothole at 15KPH. This was not done for "wheeling" but to get from A to B. The truck did well, but I would probably go for a more robust or marine grade cabinetry and hardware.