There was a lady on Ebay stores that sold original seat covers from the 1950's. All kinds of colours with those cool retro patterns. I bought a set for my 54 Chevy. Looked cool. Prices were good too. They install with hog rings over your original upholstery. Here's what mine looked like "freshy installed".
I think I paid somewhere around $125 for them. They were still in the 1950's box. The girl had an Ebay store with a pile of seat covers for various old cars. I tried to find her store now and don't see it. I originally found them by typing "vintage seat covers" in the search window. Todd