[Tf175]

If the engine is a Detroit two stroke there is also a possibility that one or more injectors are stuck , this in addition to the concerns Richard brought up . Sticking injectors can stop the fuel rack movement resulting in a "runaway " . This can result in a catastrophic engine failure . If you get to the point of starting it , do some preliminary checks and/or have a board or something handy to block off the air intake in case it "takes off " . 
The coach certainly looks good , hopefully it can be brought back to life with reasonable expenditure of time and $$ . 
Good Luck , 
Chris