I can recommend Richard Jones in Marlborough .Wilts.He is very active in Lagonda electrics , but will tackle any auto electrical problem . Email me on daveroberts.redlodge@sky.com and i will give you his details, or he will contact you.
The old Lucas Service depot at Yeovil on the Penn Mill Trading Estate, now called CARWOOD REWINDS are excellant on our MMM dynamos and are always very helpful. Good luck, Nick Dean.