@Spitfire,
Please do not repaint your red Spitfire. It will lose all its value. A big appeal of older original-condition cars these days is that they have a higher value than restored cars. Why? Because they haven't been "spoiled". I'd suggest that you repaint only the one you are restoring. Even if your red Spit becomes scruffy, do not worry, it'll be a gem in the eyes of a connoisseur.
Thanks for sharing your experience! It's a great thread, and one which I check everyday.
Wassalam,
Sami