Thanks for the links. I sent Andy the old SEV distributor which he has rebuilt (same old Andy) and installed in the car and all now running. In the meantime he is on the trail of getting the 123 distributor looked at through some electronic experts he knows – in Scotland. Will report back when I know more. It would be useful to have UK based repairers for these electronic systems – there must be 1000’s in use now across many marques.