Yes Jason, the Avon CR6ZZ is a road legal tire, but maximum width is 295/50R15 - which is pretty skinny for the back end of a wide body Mk1. Avon do a 15" 'Historic all Weather' in a 13.0/25.0-15 which is meant for a 14" wide rear wheel; but they are not road legal.
The Mickey Thompson tires...