I seem to recollect that Richard Thorne had a race disc/caliper set at some point, might be worth a call ?
I had the disc skim done on mine some time back to remove a wobble. It made it better but actually what made more difference was removing the 4 year old tyres and replacing them with new MPSS as these had gone out of band due to garage duty.
Ask any of your local independant garage and MOT centres and they will be able to point you to someone that does it, most of them sub the work out.
