Jeff,
Your ignition switch/steering lock should be the same as on my 1934.
The key operates the steering lock and is not necessary if the steering and ignition are in the unlocked position ( i.e. the ignition lever will turn up and down freely ).
There should be an electrical switch attached to the back of the assembly by the two threaded holes you have identified. The pin that protrudes between these two holes is attached to the on/off lever and should move as you move the lever to the on or off position. This pin is the activating pin for the elecrical switch.
To remove the lock cylinder you actually need the key ( depress and turn anti clockwise from memory ) in the absence of a key this will be a locksmith task.
The bracket is held to the dash by 2 bolts. One has a threaded hole in the bracket, I think the other is a bolt with a nut.
The bracket is secured to the steering column by a single bolt on the left side, these are a security type bolt with the head snapped off at the factory. I had to drill mine and remove it with an easy out. I replaced it with a normal hex head bolt.
_________________________
Stuart Syme
BCA#37072
Buick Owners Club of Western Australia
1930 Model 47 sedan
1934 Series 40 Roadster
1950 Model 56S Super Sedanet
1942 UL74 Harley Davidson