Tom, IMHO, your priorities should be water leak damage to the floor and consequent frame damage, and damaged body panels. The latter can be very expensive to replace. The former, frame damage, can be terminal. A pal, John, who I meet every winter in the Keys, bought a 34 footer of that vintage, and it has gone straight away to the salvage yard to be scrapped. The frame was totally rotted out, way beyond economical repair, and the damage was not visible to casual inspection. Using the search facility, you will find much advice on inspecting a possible purchase, but keep rotten flooring, water leaks, frame damage and damaged body panels as your priority. The model year and extent of use are way down the priority list for me.
Nick Crowhurst, Excella 25 1988, Dodge Ram 2500 Cummins Diesel. England in summer, USA in winter.
"The price of freedom is eternal maintenance."