I can add to the recommendation for Newton Ellis in Liverpool. The fixed the broken frame counter on my little Yashica 72E half-frame, and their price was within their telephone diagnosis when I described the problem to them. When the camera came back, they'd also got the selenium meter working, and tightened up the wobbly lens assembly, at no extra charge.
I can also recommend Protech Photographic, at http://www.protechrepairs.co.uk/. They were recommended to me by other Contax users, and they repaired my Contax 167MT when the electronic readouts on the LCD and in the viewfinder packed up. Once again, spot on with the telephone estimate and diagnosis, and a speedy turnaround.