The Center Caps back then were either really, really big or really, really small. They had made their first appearance on cartwheels and wagons – then they slowly evolved into the “things” that we know 
them as today.
A lot of the Center Caps that were made from the 1950s to the 1970s were made out of stainless steel – like the Ford Bronco Center Caps that you can see on our site: Hubcaps.com . The rest of the wheel (the thing that it went on) was usually made out of wood or a lot of different fitted metal parts.
As of now, you can find Center Caps that are made out of both metal & plastic; they’re usually used on either OE Alloy Wheels or Factory Styled Steel Wheels.
Where are your Center Caps?
Mykalanne.