The low voltage code could be caused by a dud alternator or even a bad connection somewhere, I think a dud connection is more likely as the car cut out, but did NOT have a flat battery as it was able to restart.
They have had issues with the main ignition switch contacts burning out but that should/was sorted well before your age of car I thought.
If all Halfords monkeys are going to do is put a metre on the car to read voltage it won't tell you a thing, your battery is obviously ok as it starts the car.
tabetha