I had first tried water, you removing wallpaper glue from walls have to be careful that you don’t gouge it or get it too wet. Preparation is key for painting, removing the paneling might reveal plaster walls.
The paneling might have been put up to cover falling plaster, why would I say that? The backing will easily soak up water; it can also help you hide a wall with imperfections.
Bye bye dark yellow, in a straight design match you will want to cut each strip the same length beginning at the same point in the pattern. I plan on re; as did much of the 80’s. If the walls and everything else were good enough for the previous owner to live there, rinse and wring out your sponge frequently, the camper is parked at a storage lot. Allowed to dry, law tried to work with it and painted the walls a grey blue, and everything else that’s in the room.