\'63 Fairlane back seats

I was given an interior from a '63 Sport Coupe. When I put it in my '63 hardtop, the back seats were smaller in width by about two inches and the bottom part didn't fit in the well. It wouldn't even snap in place. It almost fell into the seat well. Now to further complicate matters, I ordered upholstery for the car and they barely fit the original frames which came out of the car. Since the sports coupe seat didn't fit well, I opted for the original seats. Did Ford in their infinite wisdom really make two different interiors for the same car? And if so, what is the difference in the rear door panels that would require the seat to be two inches narrower? And yes, they are Fairlane seats. You can tell by the pattern of the upholstery.

Thanks!
Mr. Ed
[addsig]