With a good "ear it should be possibly to advance the timing till the engine sounds sweetest on idle and then retard very slightly from that point, afterwards roadtest when warm pulling up a hill in a high gear to ensure no pinking/detonation from over advanced timing. Remember the timing marks on the car are a good starting point but were in the day when petrol was higher octane than the rubbish we get now.
As points are grey sounds like condensor OK, a faulty condensor soon messes up the points.