RH- 67 dart back door

Hollander (42nd Ed, 1976 - Section 9A) shows:
67 Dart rear - #1925
68-76 Dart rear - #1996
67-73 Valiant rear - #2006
74-76 Valiant rear - #1996

interchange section at back of Section 9A states:

#1925 fits 68-76 Dart and 74-76 Valiant (both #1996)
so apparently the 67-73 valiant rear doors did have a "divisional" identity
rear door - guess the rear lower crease was moved to "align" with the dart for the 74 / 75 / 76
model years.

In summary, a 74 - 76 valiant RR door would work for you but not earlier years (67 - 73)
the 75 four door (valiant) i posted a few months back would have worked but it is already gone to the scrap heap in the sky.