Will a 70-72 Duster/Demon Rear Seat fit in a 68 Dart?

Just tried a 74 Dart Sport rear seat in a 69 Dart. The base is close but the wheelwell cutouts are bigger as noted so there's visible empty space. Also the mounting points are different.

Maybe if you are mini tubbing it could work out, not sure.

The back is also close but there are small differences. The covers seem to be close enough to fit either one. I have not fully installed one to verify good fit.