Joe, joe, joe. You find clues where you find them. Most photo studios could provide prop outfits but how many had boots to fit? Ive seen several cowboy photos in a studio with shoes not boots. And shoe styles have changed over the years. Like I say look for little clues if you can. Shoes, hats, saw a wrist watch on one photo that was as thought to be old. It was old but about fifty years short of what they thought. Ended up being a son of the person they thought it was.