MG Car Repair: Ignition switch, moss motors, key movement

Question
Barry,
    I have a 1973 USA MGB.   I have a problem with the ignition switch.   Car cranks when jumped from the relay.   No voltage on white/red at switch with key in the start position.   The key movement feels spongey, no return spring type action when key is turned to engage starter.   Do I just need the ignition switch example,
www.thepartsbin.com/repsite/mg~ignition_switch~reparts.html or also the lock.   Is the spring to return the key to the on position from the start position in that part?  Thanks in advance.

Answer
Hi John
The start position of the switch has failed so you need a new switch.  I am pretty sure the return spring is also inside the switch, so just replace that part, not the keylock.  It is only held in by a tiny grubscrew.  Phone Moss Motors and ask them, just to be certain.