Finally got to tearing into my column to replace the key-in buzzer switch I thought was bad. Turns out I didn't need to buy the switch after all. Originally the buzzer would sound even without a key in and door open. The broken lever must have jammed the switch permanently depressed. It eventually jarred itself out because I found it inside the collar.

Any recommendations on where to buy a 1970 E body ignition cylinder? I plan to swap out the tumbler pins too, so my original key will work. Thanks.

That's a 70 type with the "knife" type hold in tab. Laters' have the round pushbutton.
Early were also a satin finish. I once adopted a round type cyl to a slot column by drilling a hole for the
button (where the slot is) to release into.
Not that difficult, but better then waiting to find the early style.

Repops are available in both styles, was wondering if one vendor is favored over another.