That camper is from 1990 and looks to be in "adequate" shape for its 27years.
Davlin stopped making campers in 1995. At the time, they were somewhat popular here un Germany - I have seen a few.
They did make models that fit on the old Rangers and comparable trucks. Those make up about 95% of pickup trucks here. The one you are looking at has no bathroom and looks fairly small on the pictures, so it may fit. At least technically, which means that the floor fits between the rear wheel wells.
Weight is an issue. Many small trucks here are crew cabs with very short beds, and putting a camper on these very easily overloads the rear axle (and lightens the front...)
The campers were of conventional construction - wood frame and aluminum siding. This particular one looks like it has seen at least one makeover. New flooring, painted furniture. Be careful if you look at it and insure that it is structurally sound. Especially at the front corners where the jacks are mounted.
2014 Ford F350 XLT 6.2 SCLB + 2017 Northstar Arrow