[Graham]

Austin A30/35
Morris Minor
Fiat 500
Ford Anglia

Most small cars raced in that era had wheelarch work but a 52mm limit would certainly keep tabs on things.

The Fiat 500 definately, and I just seen on the PSR website the Riley Elf, the Mini Pick up truck and the Mini ERA Turbo which could be permitted. 
The Austin A35 perhaps ?

I think the Morris Minor and Ford Anglia perhaps could be in a seperate class for small Under 2.0 litre Saloons ? but in the same Event with the same width restrictions.