Technical What are these?

I've had three of the covers for some time. Fill me in on what they are and does anyone have another so I can round out the set?

Sent from my SM-G973U using The H.A.M.B. mobile app

 

Think they are Buick, trashed the three I had last week. The money is in the missing centers. Bob

 

Something like this except this center isn't removable?
https://i.ebayimg.com/images/g/DgEAAOSw9LBgAchP/s-l1600.jpg

 

I thought they looked like they would fit over a '35 Ford wire wheel and it's stock hubcap to make it look like a full wheelcover. Have any handy to try?

 

This is '53 Buick Super and Roadmaster............

Ray