True 67,8 & 9 Formula S Barracudas

I respect peoples privacy. There will always be those who will not participate do to their own reasons for which we need to respect. So, in building a registry, how much info should be collected? It would seem that some form of "proof of authenticity" be included. Cars with missing VIN or fender tags could be included but noted. Maybe also- "A" body Dodge and "A" body Plymouth.