[Mgs] MGA Ignition switch

[Robert J. Guinness]

In my ongoing war with the electrical gremlins, I am replacing my 
ignition switch on my MGA 1600. The engine would shut down as I was 
driving, but moving the key to the right would bring it back to life. 
The new switch assemble came in two pieces: the key tumbler and the 
switch.  Moss #169-108.  I put the tumbler in the switch  in the only 
way it seemed to want to go in.  But the key will not turn the tumbler 
within the switch.  Did I put it in wrong (in other words, what is the 
correct way to install the tumbler into the switch)?  How do you get the 
tumbler out of the switch?  Thanks in advance.
-- 
Robert Guinness