This magneto appears to have been originally a Lucas K1F and it has been ungraded to take on the appearance of a K1FC the competition version.
It has had a through overhaul with a rewound armature and new slip ring along with new brushes, seal, points and fixings. There is a new K1FC end cover and it is a manual advance type with a good cam.

It will produce an excellent spark when the armature is flicked over by hand in an anticlockwise direction when looking at the drive end making it suitable for Velocette singles. The photo shows the spark when the armature is rotated at moderate speed using a battery drill. The armature taper and screw thread is in sound condition.