Rear seat questions

Hmm, that upholstery pattern is correct for a 67 Barracuda. but all three Barracudas had different rear seats -- fastback, convertible, notchback. I only have the first two -- your seat would have to be off a notchback, if it's off a Barracuda, I would think. I don't know why exactly it would be narrower than a Dart, but the rooflines and rear window shapes are very different.