When Cheyenne is shot at by Elmer in several scenes, you can see that it's his stand-in instead.
When Johnny shoots Lafe, Lafe throws himself against the side of a building and a support column across the alley. Both the building wall and the support column move substantially, indicating that they are flimsy sets and not what they appear to be.
At 17:17 a boom microphone shadow is seen.
Cheyenne's stand-in rides up to a building and dismounts. The next scene shows Cheyenne in front of the Sheriff's office. You can see it's a different building as the glass window and the glass above the door is different.
Cheyenne's stand-in also plays a townsman in the bar, part of the lynching mob.