The studio photos look very posed and might even be doctored; they have a sort of wrong-head-glued-on-body look. Most photographers of the 1870-90's era had costumes and sets ready for the purpose. I have a c 1877 photo of my kinsman wearing a buckskin suit! Some of the posed shots also suggest that - the sitter above with the dog is not even holding his gun (he looks scared of it!), but has a hand on the dog.
K.