Dupli-Color makes vinyl/plastic paint that is available almost anywhere. In my experience it rarely matches, though.
I've had the best luck with SEM brand paints for interior parts. Check with a local automotive paint store. It's about $13 per can.
I replaced some interior parts recently with aftermarket pieces and used the SEM product on everything else. (Interior color change, Light blue to dark blue). The match was perfect. On your original parts, you may not get a perfect match due to fading of the original pieces.
The SEM product sprayed and laid out great too. You could almost just throw the can at the parts and it would look good.
Don't forget to use the recommended adhesion promoter.