How long will it last?

I've regularly seen RVs from the late 1960s and early 1970s in use, original, and restorations from as far back as the 1940s, but mostly late 50s and early 60s. A lot depends on care, but also conditions of storage and use, part of that being climate. Just as with cars and trucks, e.g. here at 20 years old we might be dealing with faded paint and dried out rubber and plastics, where my family in Detroit has to be watching out for rust on a car that old used in winter.

But the is also the issue of materials and construction methods. The really old RVs I'm seeing in use have framed construction and metal covering, 21st century is a lot more laminated panel wall, petroleum-based synthetics and adhesives for materials, I don't know how long that stuff lasts. I do know that some manufacturers have had problems with early adhesive failure ( i.e. between delivery and sale), and I've had to deal with galvanic corrosion problems caused by two different metals held together by incompatible sheet metal screws, leading to the sidewalls on one of these laminated plastic boxes separating from either roof or floor. Problems like that will also depend on climate.