Jay, I have used a firm called cylinder head services in Bilston for Rover/Perkins heads & I know of other people that have had other heads done there & I can highly recommend them!! I last sent them BMW/Freelander TD4 head that was smashed, all 8 valves, seats, guides the lot, they did it on 24hr turn round & it came back like a brand new head, as has all the heads I have had done there! & they aren't expensive, if I remember right that TD4 head was about £180 all incl of new valves, guides, seats & springs. There numbers are 01902 497939 or 07977502703