The only CERTIFIED appraiser specializing in 1st gen Camaros is Jerry MacNeish. He does this for a living, has been an NHRA drag racer for over 25 years, has written 2 excellent Camaro books and has a component restoration business.
http://www.z28camaro.com/consvcs.html
Does he have a list of all COPO VINs? Nope, and no one else does either.