Bob.
One of these would make a cool toy all right! I'm thinking of building one from a Cab 11 F15A. I don't know what their coach work would have been like but it looks like you could use square tubing the same size as the CMP door thickness for framework and spot weld sheet metal to it. Screw the inside panels on so you have access to the door handle mechanisms.
Notice on that model they have the endgate hinged from the top but in this side view it folds down to use as a table (just like a 'real' endgate.) Also notice on this pic that the bottom of the added on rear cab doesn't line up with the bottom of the CMP cab. You might figure out why when you delve a little deeper in the project. Also notice that some have CMP headlights while others have the German ones; some have the push bar while others don't and some use CMP bumpers while others have a mount that lowers the bumper and use a different bumper.
I really think that most of the details are covered in the posted pics. The pic with the 2 Umbaus is from another forum and hasn't been posted here before. On that side view pic I removed the overwriting plus the radio and rifles just for clarity's sake. Gotta love Photoshop!
