Hi Forest,
I try to find somebody I can trust to do that kind of work. They should have a pit or a lift so they can easily check everything on the bottom side. A few things I would have checked/performed:
Oil/filter
Lube greaseable joints (some Newells have grease zerks on the steering shaft under the dash area)
Air filter
fuel filter/water separator
brake linings
air brake actuators
air lines
air bags
check air leveling valves
steam clean engine/radiator
check engine coolant often ignored by some mechanics. Here's a good article:
http://www.buyerzone.com/constructio...e-coolant.html
check all coolant hoses
You might contact Newell. They probably have an annual checklist.