The inscriptions on the wedding rings are from the poem, "An English Padlock," by Matthew Prior (1664-1721).
Almost the entire credited cast appeared in episodes of The Twilight Zone (1959), including Buddy Ebsen, Lois Nettleton, Paul Fix, Denver Pyle, and Warren Oates, who was in two episodes.
Mail Order Bride (1964) was based on the short story "Mail-Order Bride" by Van Cort in The Saturday Evening Post (11 Aug 1951).
The staging of the climactic shootout is quite similar to the one in "Ride the High Country." Both films were produced by Richard E. Lyons for MGM, and Warren Oates was a bad guy in both scenes.