CSX3833 is a bogus Shelby number that does not apply to any original or modern continuation car from Shelby. If it was a typo, please repost. If the car you are looking at has that s/n, post some pictures so we can help identify the source of the replica.
Based on a picture of a loose tag, and not the car, I would encourage you to make the inquiry to the Cobra Registrar: mailto: cobraregistrar@saac.com There is little data documented on that car.