Can anyone suggest an individual or firm in the vicinity of Truro (Cornwall) who could expertly repair a high-level but 30-year-old Technics SE9600 power amp? The repairs are relatively minor (selector switch for main/remote speakers only connects one channel - may just need cleaning - and the amp could ideally also do with new output potentiometers and a replacement pilot light). The amp is basically working normally (both channels sound fine though headphones) and I have a circuit diagram and parts list off the internet.