Bosch Hedge Cutter (Gunnislake PL18)

I have a Bosch AHS 6000 Pro-T headgecutter - 700W motor, 34mm blade spacing, 600mm cutting length. It is in good working order with the exception of the on/off switch which has developed an intermittent fault. Local garden machinery companies have deemed it uneconomic to repair at £50 an hour! Unfortunately I don't have the knowledge, tools (or patience!) to undertake the work myself. So I am offering it to anyone who would be willing to give it a go.