It's the hubcap from a 1678 citroen.
LOL
Reminds me of a segment on the old Phil Harris radio show. He and his buddy Frankie Remley discover an ancient treasure map that points to their backyard.
They dig and dig and finally remley says breathlessly, "I've hit something! It's big and round and looks like it's made of solid silver! And there's WRITING ON IT!"
Full of dreams of riches, Harris asks, "What does it say?"
Remley, very softly, "Packard."