Before driving CX car which has not been fitted with the approved replacement brake cylinder etc I respectfully suggest you look up the offence of driving dangerously. As I understand the relevant law if I drive my CX knowing it has a dangerous defect as indicated by the recall notice and the emails/letters from MMC I would be guilty of the offence whether or not my insurers said I was insured. I have no desire to be disqualified or fined and/or suffer other penalty (it would be difficult to avoid custody if death or serious injury was caused by a brake failure).
I am therefore very concerned about the position. If anyone out there has a contrary view t suggest he or she obtains advice in writing from a competent solicitor.