I’m guessing they’re wooden, and some appear to be from the 1920s, perhaps earlier.
I don’t know a lot about hats, except that early makers of felt hats used mercury in the process, and the accumulation of that metal in their systems eventually affected their mental stability, resulting in the phrase “Mad as a hatter.”
Originally, cowboy hats and others were functional rather than a fashion statement. Brims were flat, designed to shade the sun and drain the rain, but once movies came about, the sides of the brims were turned up to show the actor’s faces. I suppose the crease in the top kept water from flowing off the sides and toward the back.
The side “dent” is a mystery, unless it was where a man grabbed it just before saying,
“Well, helloooo, ladies.”
[Found in here.]
Tacky Raccoons 