I forgot to add that my main Electrical connector near the head-stock had some corroded contacts,which was a breakdown just waiting to happen.I cleaned these with a jeweller's small screwdriver with some 500 grit paper wrapped around it and Switch cleaner and then treated with ACF50.
It's quite common on older machines that mechanical parts are kept well serviced but electrics are over-looked but corrosion never sleeps but can be slowed down to point where it cannot cause problems