As far as the metal trim around the headliner goes...My pieces weren't rusty after 40 years. They were just dull and scratched. I sanded them with a fine sanding sponge in some soapy water.(dish soap) I think I used SEM self etching primer before spraying SEM Trim Black. The factory never used a primer so I don't think you really have to. The parts are going to be protected since they are on the inside.
The plastic interior panels don't accept paint very well. I cleaned mine 4 or 5 times to make sure they were very clean. Then I used SEM Adhesion Promotor followed by SEM Landau black. Since you are going red, you'll have to try and find a color that closely matches the factory color. I don't know if SEM has a red that is close or not. I found that the key to making the pieces NOT look painted is to mist the paint on. If you spray heavy coats, it will look painted.
Also, Herb's Parts has their own line of interior paints. I'm sure they would have the correct red you need.
