No they aren’t all the same
67-70 were I think all the same,
71 different
72 different again.
The differences are in the part that goes inside the filler neck. Depth and number of tangs.
Do a search on this forum and someone posted a clear picture of the differences
Edit: I’m in a good mood. I did the search for you, it’s in here:
Duster fuel filler pipe difference between years