Yes, Steve is right of course and I should have said that non DoT treaded tyres, are also avaiable that fit cars like mine, and I'd be happy to run those as well.

Also to say that I wasn't thinking of Ray and his Arrows/ERC series in the tyre debate, only of those events and series where true historics are sought for the grid (and then told they have run modern tyres that don't fit the car...).