Sorted now, no damage to the steering lock mechanism, though they sheared one of the puny bolts that holds it in place. Had to remove the remnants, cut a slot in the broken stud with a dremel and screwed it out. Dismantled the ignition, soldered in new wires to replace the stripped ones and joined to those to the existing loom, inside a bit of narrow inner tube. Runs well though still need to do a brake service and oil change at its not been properly on the road for a couple of years.