Welcome to the forum Dean.
Here is a Brochure
and a 99 Owners Guide
for the operation of features on coach lowest we have.
The coach had options that would include winter options for cold weather camping which you may have on coach something to check.
The furnace will send heated air into the tank compartments to keep them warm and another option could be heat strips under the tanks there may be a switch in the water bay that puts on a 12v fan in foil tube from furnace for a quicker heating.
The Ford 460 use to have manifold problems but previous owner may have install a Banks System to eliminate or just had them remounted.
Need to check tire dates, climb on roof and check seams, the rubber roof for age and soft spots.
If you Know the Vin # or coach build number by Newmar you can input it in the COM_NET2
link and find possibly info of when and what materials were put in coach.
Good luck, I had two coach's with the one slide made for more room up front and plenty of cloths storage in the bedroom.