This set was given to me by my late father-in-law. He ran them for 20+ years on a '59 Chevy truck. I want to use them on my '41 Pontiac. Father-in-law never knew what they were off of. I suspect Thunderbird because of the bird in the center but cannot confirm that.
Thanks fellow Carolinian. Now I know. I have other sets of full covers but these have sentimental value.
I still think the "thing" in the center kinda looks like a bird, if you don't look too closely. Ha ha.
Aftermarket flippers as Jimmy six said The old JC Whitney catalogs did have pages of them but you could buy them at local parts houses and a lot of other places including Sears and Wards back then.