The builders plate has the paint code. It's on the upper left of the firewall in the engine bay. Second line down it should say "Farg Colour" and have a number stamped next to it. If you have a local auto body supplier, they should be able to look up what color that code goes to. If there is surface rust, I reccomend sand blasting. I've had mixed results with various rust sealers/converters. Sometimes they work, but I don't like taking the chance on the exterior of the car. To get the surface texture to be a bit closer to the rest of the car, it will probably have to be wetsanded with 2000 grit and buffed out. For buffing out paint (both original and newly sprayed) I use an occilating buffer with a foam pad along with "Evercoat" medium compound. This brings the surface back to life, and then I buff it again with 3M finish compound and swirl remover using a finer/ higher grade foam pad to give it a nice gloss. There are other things you can do after that to keep and protect the finish, but alot of it is personal preference. I'm partial to Meguirs products.
Best of luck with the car. How are the rocker panels, and rear wheel arches?

-Nick