I think this would be an awesome setup for the FWC. As you know, we were close to purchasing a custom FWC and planned to use the same "road case" materials for the interior. Since the FWC is mostly square, it would've been a much easier project. As mhiscox and Paul Jensen can tell you, there is not a SINGLE spot on the Sprinter where two surfaces are square to each other. The only flat surface in the entire vehicle is the rear section of floor. I had to retire my measuring tape after this one.
BTW- The aluminum in your camper looks awesome! Very nice work.