I think an appendix in Palmer's book identified Pepper Red in 2 DuPont paint variants - the baking enamel B797-7751, and the air dry enamel 99-77513. Please let us know if you can follow-up with these numbers and if they can still be x-referenced by paint shops. Thanks.
Edit - Did some Googling for Pepper Red and found the following citations on forums. Have no idea whether these are correct or not.
1. DuPont Centari (acrylic enamel) that I have used is code #21821A. 2. PPG Concept Acrylic Urethane Color is DCC78015 H. 3. The code for pepper red is 2622-A from DuPont