Take it to a INDEPENDENT TRUCK mechanic and have the motor and tranny looked over.
Do not take to an RV dealer but to a good truck mechanic.
MAke sure genny works if the unit has been sitting without being exercised that could be a problem.
Is the fridge original? if so it is 27 years old and could be near the end of its useful life.. Expensive to replace unless you trade out to a residential fridge but you do not have electricity at the site so you need the propane capability.
For comparison I bought my 1990 Fleetwood Southwind with the 454 engine in it for $4000.00 but it needed new tires which set me back about $1500.00.
On the other hand the fridge is a a 1998 model as the original bit the dust when the previous owner had it.
