Thanks for the advice re: Haynes, you've confirmed my suspicions!
As for the misfire, I've changed the plugs, leads and distributor cap. The car has an intergrated coil/distributor.
Is has a slight misfire when warm, but it is at its worse, for the first 2 mins from a cold start. I don't have any ECM lights on, so that makes me suspect something on the HT side of the ignition.....do you think it is worth me changing the rotor arm?