Got back from an MOT after the old girl went straight though with only the obligatory rust warnings, only to smell overheated brakes. Turns out rear calliper piston has seized on the 5 mile trip back. Is there any cure other than a calliper replacement? If not where is is the best place to buy one, have had a quick look on the net, prices varing fom 46-102 quid, are the cheaper (PADDOCKS)ones OK?