rear seats

Way back when my youngest brother was in high school he bought a white 1969 dart. The emblems said GT Sport. It had a 340 and a 4-speed, with a green interior they call champagne I think. Sort of a light green. Here's the thing.It had rear bucket seats just like first gen chargers. Not seats that were identical but very similar. These looked factory original, as they seemed made to fit. I have never seen another like it. Was this option available or did the factory create a one off for a big wig, or did someone just do a really nice job? Any input?