Interesting thought, but have not personally tried it. Door skin looks similar enough, but can't vouch for the inside door opening shape being compatible, and no Duster/Demon/Dart Sport handy to get measurements from. Don't think the early vent window & frame will swap into a later door without a bunch of work. Door lock position is different, as are door latch levers, armrest attachment, window mechanisms & cranks, door card size and shape, and most of the linkages. Hope you get some feedback if the main structure will physically fit.