Westfield Elevens

Not sure that Dunlop racing tyres are "illegal" to run on the road. Tyres just have to be suitable for the application and have sufficient tread. There were some anomalies between the Construction & Use Regs and the MoT, but I think running Dunlop racing crossplies on the road is technically legal. Of course, because they don't have speed ratings on them and have not been type approved the onus would be on you to prove they were "suitable".
And, should you have a mishap, I'd expect a tough time from your insurance company, who would look for any excuse not to pay out.

Here are the regulations;

http://www.motuk.co.uk/manual_410.htm

See about half-way down; 4.1 Tyres (condition) "Not for highway use" in column one. Racing tyres are only road legal if E-marked. Most are not.

This site is really useful. For example, it explains how a 2005 vehicle has it's 1969 engine's emissions checked.

Well, I had XZX on my Lotus 7 Series 1 America with the 15" wire wheels (standard factory fitment), and they were HORRIBLE! Worse tires ever. Really.

The car was really undrivable until I installed the proper 15" racing Dunlops. Then, all was well.

I run 185/70/13 tires on my 13" wheels. There are some very good 185/70s available.

The minimal clearance for the tie rod end is normal with 13" alloy wheels. The original set up for the cars was 14" wire wheels from an MGB. Just be careful when you have the tires balanced.

I found that it was important to have the tire shop put the stick on wheel weights in towards the center of the wheel and/or the outer rim so that the rod ends don't knock them off.