Piece of key lodged in fork lock, probably need to remove cylinder to extract it. #'s match my good ignition switch w/ keys. It's a '66 CA77 and it is in the unlocked position. There is a small gap at the top of the round cylinder end that is squared off. I've tried inserting a sliver of credit card to depress the pins fully, but it won't budge. Is there a swaged retaining pin somewhere that I have not discovered? Any clues appreciated.