The song Malaguena is played in the cantina, but the song was not composed until 1928.
Wagon Train Tracker: Another trail change for the train. Early in the episode Coop Smith makes a map reference to a tribal war party in southern New Mexico while at a fort, later named as Fort Fillmore, N.M. (though destroyed during the Civil War in 1861, and episode year is 1870). So the train is now moving west on the Gila Trail, through south central New Mexico.