Demon door?? Which others fit?
No Not without major surgery.
Describe the "major surgery" needed. The handles and interior door releases are in the same place, and the outer shell is identical. The outer door skin is the same from 67 to 76 as long as you leave out the '67/68 post cars and stick to hard tops or the Duster/Demon body. The door frame changed with changes to the interior, door handle location, side impact bar etc for the 73+ cars. There were also changes to the internal mechanisms for glass mounting etc on shorter year runs, but that only matters if you already have the glass and try to mount it in a door with hardware from a different year.
The problem with using a Dart door on a Demon or Duster (or even a later dart sport) is that the internal window mechanisms and hardware are different and mount in different locations (different window track locations, etc). The door shell/frame is the same, but you'd have to drill the holes in the door frame to mount the window crank, window tracks, stops, etc. Since a '67-69 door would have to be from a Dart, you would need to drill all the mounting holes in the door frame for the '70-'72 Demon/Duster window hardware.
I have two sets of early doors for my '74 Duster, one from a '72 Dart and one from a '70 Duster. Since it's a '71 demon tribute, and because I dislike the later plastic door trim, I wanted to replace the later doors in favor of the earlier ones to change the interior over. From the outside the doors are the same, the pre-73 doors obviously have the metal tops and earlier handle and window crank locations, so the later glass and interior parts are not compatible. But the shell itself is basically the same. The '72 Dart doors I have are in a little better shape, but I'm using the Duster doors just because I don't feel like locating all the mounting holes for the window mechanisms. Obviously, if you use door shells from a Dart you still need to get all of the glass and window mechanisms from a Duster or Demon, as the internal hardware is different.
I believe that the '72 model year glass is different in how it mounts, so the internal hardware is a little different, meaning you wouldn't want to try to use '72 glass with '70-71 hardware. Keep the glass and hardware matched up and all you should have to do is locate the mounting holes.
