That was my thought, and I did find the blueprints from GMC for the 26 footer. I was thinking it would be great to have the RV, and then have it convertible to the armored version.
Also, probably sounds like a small thing, but a big selling point for me is that all of the 'glass' can be cut from flexible sheet (windshield panels have to be curved of course, but it's a single bend); I can get glass with complex curves 3d printed in clear resin or cast, but it is such a PITA and a significant amount of extra work for so-so results.