This is a rather rare gadget, never used in the large North American market for MGA. The Neiman key operated steering lock (common on other cars of the time) included the ignition lock switch and key operated start. Redundant holes in dash for key switch and pull start knob were closed with special snap buttons. Presumably there would be a starter solenoid mounted in place of the pull-start switch, but I haven't seen documentation on this part yet.

The steering and ignition lock with key start shown was fitted to some European export market 1600-MK-II cars starting September 1961. Steering lock was required earlier in Sweden from May 1961 and in Germany from July 1961. I have one report of an MGA originally dispatched to France also having the steering and ignition lock set-up (photo above is from that car), but not known yet if it was standard issue or special order.