My factory diesel was a northern coach that was not used in the winter but regularly used in the summer on smaller excursions for a long time. The PO before me put 10,000 of the 80,000 miles on her over a period of 5 years. I've put 5,000 miles in 5 years, with one season lost due to the renovation I did.
I agree with Mike, finding a factory diesel (or even one converted to a 12 valve Cummins), northern coach (less sun damage), used on a regular basis in the summer, and you have it made.
If the owners have changed things like the ancient OEM Univolt converter to a Progressive Dynamics unit, or changed the air system, that's a good thing.
Per Mare, Per Terram and may all your campaigns be successful.
ďItís a recession when your neighbor loses his job; itís a depression when you lose your own.Ē "Harry S Truman"