Dash Frame Paint?

You can use SEM products landau black and dry spray the final coat(s) to get a consistant desired finish. Worked for me. Collars on steering column repainted with it match the dash housing perfectly.
The SEM vynil and plastic spays really are just a laquer based paint with additives to make it flexible. The only tip for the dash house is LOTS OF PAINT ! Spray can paints are mostly vehicle with very little material. Very thin coverage at best . I'd spend 6 cans on a dash to get coverage that isn't easily scared.
and by the way... factory never painted the underside but if you leave it in a light primer or paint it white it will be much easier to see when working under there. good luck