Because of the floor hump you want to look at mid size rear wheel drive cars so next time you are at the local Pick-A-Part go armed with two things a note book and a tape measure. Some guys have used mid 80's Cutlass seats,if I remember the width needs to be 55" or less so take some notes as to the measurements in your car to compare against.
A couple I pulled off the internet while researching..... Chrysler LeBaron front and rear seats (don't know the year).... 2003 Chevy Astro van 55 inches wide......
I have seen 63 /64 T Bird "wraparound" rear seats used in 49 to 51 Fords many times and they look pretty cool. Not sure about the dimentions vs the 52 but should be close.
What's screwing me up is the arm rests for the rear seat. If memory serves correctly, the backrest starts at about 4ft (bottom) and goes up to 4ft 6in at the top.