They're later Dodge hubcaps, like '73-'76 (maybe '72 also?).
I had a '73 Swinger and a '74 Dart Custom, both came with them new. I've got a friend who has a '75 Dart and they look awful on it IMO, your '64 is the only car I've ever seen them look half decent on.
I've always loved the Cragar S/S and they're especially cool on your car since they were introduced in 1964.