just pulled in to mrs_d's place of work to pick her up on way home. I was early for a change so I turned the engine off. bad idea. now it won't start. nothing at all from the starter motor.
my uneducated guesses are in order of most likely (in my uneducated mind):
a) starter motor
c) battery - but it was good enough to run all lights & radio, even a very flat battery does turn the starter a bit
d) totally seized engine for reasons unknown - it's not the oil -
e) it's French, so it'll be an electrical problem. '56 plate Citroen C4 1.6 petrol.
anyway, it took me 15 minutes in the phone queue to get through to the RAC, an 0800 number from my mobile phone; estimate is up to 2 hours before the patrol can get there.
We got a taxi home, I'll go back when RAC rings with an ETA.