The phrase "hens teeth" springs to mind. You'll be doing really well if you can get a pair of pre-64 seat frames. Searched everywhere last year and only found one pair that needed a lot of work.
I have to ask, why so specific with the year? Do you have a '53 car?
Its like this Kieran, if you don't ask you'll never know.
Yes, is an August 53 Oval which has a lot of the Zwitter parts/characteristics. The herringbone pattern was one of the fabrics available in the Deluxe options in split and ovals from that year, which is what the back seats are and the door cards are in my car. Its incredible how original the car is, but in the late 50's the front seats were replaced with later oval (adjustable back rest) type at the request of the then owner. The replacement seats are in incredible condition but are the wrong color.
Maybe there is somebody out there with earlier seats in a later car…lol
I could of course re-upholster the current seats but they are in such good original condition it would be a shame.