From the Avon website
http://www.avonmotorsport.com/historic/historic/cr6zz"The CR6ZZ is a range of road legal radial competition tyres suitable for classic performance cars. They are an all-weather tyre designed to be used for competition driving in disciplines such as classic road rallying, trackdays and circuit racing. "
"The Avon CR6ZZ is EXEMPT from the EU tyre labeling regulation EC1222/2009 because, The tyre is designed to be fitted only to vehicles registered for the first time before 1 October 1990"
So its exempt for the labeling. I can't believe that it will not be OK for the MOT when they look at the tyres for the EU tyre labeling; or will it be a problem if it is used on pst 1990 vehicles?