Ailz put the shout out for an electrician on Freecycle- and Steve's wife recommended Steve. He's a middle-aged bloke with a beard- and we liked him so much we felt easy about leaving him in the cellar- still fiddling with fuses- while we went off to the Trafford Centre to meet Alice. He didn't understand our problem any more than any of the other electricians have done, but he worked round it - and now all the lights come on. For this- about an hour's work- he charged us £20- much less than I was expecting.
The step-lift has been fixed too- until the next time it breaks down.