You should be able to get all the info you need from your local DMV/Registration office.
Classics are 25 years in Texas, I'm not sure if this differs form state-to-state though. Also, how do you define rare? The 93 Cobras are limited production, and not that rare yet. A 65 Daytona Coupe, Shelby GT350R, and maybe a 93 Cobra R are rare.