I think it was Humbrol that did a vinyl paint, I used it extensively on some of my early cars. The first time I tried it was on white headlining in my Opel Ascona, it was sound but tatty looking despite much cleaning so I decided to paint it black. I started with a brush on the pillars that were glued down and it came out quite well, even the brush marks disappeared so the next day I moved to the headlining. I whacked the paint on with a 50mm brush ending up high as a kite from the fumes! My heart sank after an hour when I looked inside to see the whole headlining sagging and wrinkled, the spirit had softened it. By morning though it was tight as a drum and a perfect finish.
Crap on some of the injection moulded plastics though.