When the boy is driving the wagon and the men are shooting at it, in the shot from the rear it is clear an adult stuntman was used. The amount of his back seen is much higher above the rail than when the boy was shown driving the wagon.
When father and son are looking over the property and home to purchase and sitting at the table he mentions twice about needing to buy a plow for $20 yet in the opening scene, strapped to the side of the wagon is a one bottom plow shown which is shown in a couple of shots.
Just after the opening robbery scene, as Frank Ferguson says "They're outlaws, desperadoes, murderers", a horse in the middle of the shot has a large bowel movement. Usually in those days that sort of thing wasn't shown onscreen.