My guess is that it started out as a 3800 Rug van with only a driver's seat. They would haul 12 ft. rolls of carpet which are heavy! Looks like the coach builder made a crew crummy out of it. Probably oil fields based on the Colorado build. Here in Washington I've seen similar rigs that were owned by logging companies. One that came my way for work was a Napco 4x4. Caked with grease and mud even years after it saw its last high-lead logging show. 54 or 55 with a divorced transfer case. Went to the steam cleaner first thing.
