I had a bunch of old lock and ignition keys and parts long ago and was able to find a key to get the tumbler out .I would guess to say the locksmith should be able to pick the lock to get it to turn to remove it .I found that most the inners of the lock are worn out from years of use and the tumblers are only soft metal (brass).It would not hurt to find a bunch of keys and if they fit in the cylinder wiggle them around to see if you can find one that turns to get the cylinder out .After I got mine apart I was able to swap the good tumblers in the cylinder to make the door key and ignition match.
