Oswald

I recently purchased a 1963 Avanti R1. The previous owner had put Daytona wire wheels and P215/75R15 tires on it back in 2005. The tires still look new, but obviously at 19 years old need to be replaced. I have a question about tire size. I want to keep the Daytona wire wheels. When I look for tires for the '63 Avanti on Coker Tires, the recommended size is P205/75R15. Should I downsize to P205/75R15 or replace the current tires with P215/75R15 tires? Any advice will be much appreciated! Joe