Bet the ignition was changed. That's what happened to me with both of my 'birds. Three keys, one for the ignition, one for the doors and one for the trunk/glove box. I just had the door locks changed to match the ignition. They must have had a lot of problems with the '69 keys and ignition. I've known several '69 GM's where the keys broke off in the ignition. Or it was programmed obsolescence.