i really hope you get it back.
They’re called “shave keys”. Older vehicles with double cut keys wear down inside the lock cylinders and the keys wear down too. Thieves will have a ring full of well worn keys for target makes, usually pre-2001 Fords, Toyotas, and Hondas. Usually one of the dozen keys of a particular type will pop the door and turn in the ignition and they’re off. Rekeying an older vehicles isn’t cheap and they prey on that.