Thanks both for the help, I managed to Solder the wire to the pick up which was an absolute pain but it stuck eventually and the loco works good as new.
I have another question that relates to essentially the same Jinty chassis..
On another model I have, I can see the coper pick up that is supposed to sit behind the wheel has worn away so does not touch the wheel anymore, its fine on the rear wheel, but the front there is now a gap, is there anything I can solder/fix to this so that the pick up sits behind the wheel correctly again?
I had a quick look online but could not see any helpful suggestions for this.