When I re-did my LX years ago for the exterior satin black stuff that wasn't over acrylic paint I just bought a few of the $2.50 "export" brand cans of flat black. It looks as good as the original stuff, is very forgiving and sticks to most anything. There isn't huge amounts of painted stuff on a Torana but it lasted for years where I used it, like the side plastic between the doors and quarter glass, windscreen wipers, headlight surrounds, grille etc.