When we bought our '86 Puck earlier this year I also decided to paint the interior. It was all too brown and beige for my liking though in generally good condition. Decided to start with the walls and having painted them white, I've now had a rethink and decided that the 'wood' looks ok. I also used a Johnstone's primer and then vinyl matt emulsion. Seems to be ok, but only time will tell! I also recovered the seat cushions, changed the curtains for roller blinds and wallpapered the fridge.
My advice would be to take things slowly, changing one thing changes the whole look and feel in such a small space.
Also looking forward to seeing the photos
Jo