You should be able to find a Dodge Factory Service Manual (used online) which will cover most of the chassis portion (including wiring) of the motorhome. For the coach side, you may as well be mining for unobtainium. What you see is what you get. Most replacement appliances for the coach are "kind of" universal fit so you will need some carpentry skills/tools to trim the rough edges and "make" them fit. Just be sure (in advance) they are close in size, voltage, venting, plumbing, etc. to what you currently have. (or what was once there) In short, don't try to make a double wide residential refrigerator fit into the space of a college dorm style icebox.
Chum lee