My guess is it is a 19' Ford E-350 with 6.9 diesel
Mobile Traveler. Were made from Mid 70's? to Late 80's? This one looks closer to Mid 80's judging by the windows used and Ford Chassis. Windows look OEM too. Must been right when they switched from Dodge to Ford. Cause the camper box is more of the type the used with the Dodge..... where on the Ford they molded the area that truck and cab meet little different. (see pics). Orrrr.... someone put a Ford front on/under an older Dodge style camper box. My guess is the first one.