I can fully recommend:-

Palmer & Phillips
Peterley Rd,
Cowley,
Oxford,
OX4 2TZ
Tel - 01865 749600

They were fantastic with my old 145 Cloverleaf and it's various electrical issues, especially the airbag warning light

My 156 has only been in for annual services but am still on first name terms - must be the visits in between services for oil