16 years ago I roll-on painted some old hanging wood & metal cabinets in my work shop at home with a white gloss Rust-Oleum oil based paint. The paint leveled okay with a consistent texture like a refrigerator, because of using the roller. The paint has held up extremely well with an excellent bond to both wood & metal surfaces. Chemicals and grime does not penetrate the finish. Grime cleans off easy, the finish stays glossy, and not one paint chip as of yet. The gloss finish is great for my work shop cabinets but I think would be horrid looking inside a motor home. Maybe a satin paint would be more appropriate.
I think in-general, an oil based paint will penetrate & bond to materials and contaminated surfaces better than a water-based paint. Because I rolled the paint which offers a slight texture, the finish might hide imperfections with patching holes and such.
I have seen some creative painting in people's homes. They alternate flat and satin vertical stripes to look just like wall paper.
I do need to mention that using an oil based paint will require a lot of ventilation. Plan to place a fan up front in the van portion to get air flowing through the rig while inside painting.