Most of the doors in the buildings in town are equipped with modern brass doorknobs and dead bolts that you can buy at Home Depot. Not exactly period hardware.
Early in the movie, the character Selina Stevens asks her husband to carry the Crock-Pot inside for her because it's too heavy to lift. Crock-Pots, the term and the device, weren't in existence until the early 1970s.
Coins used in the movie are all modern. Close up of the card table reveals Washington quarters and Lincoln cents.
In the bounty hunter's room you can plainly see where the sheets of drywall on the outside of the wall studs butt up against each other on one wall, while another wall has OSB board o n it. There was also painted over OSB board visible throughout the movie.
Drywall or "sheetrock" didn't start appearing here until between 1910 and 1930, and OSB board didn't come into being until the late 1970's.
When she is walking towards outhouse to get old guy there is a light fixture laying on crate. It's brass oval with two light bulb holders coming off of it. It's a very modern bathroom fixture.
The shadow of a crew member is seen on Joe's jacket when Lee and him dismount and scan the rocks for movement.