Howdy!
I came across this hat at "Brims and Trims" hat company while in Texas about a year and a half ago. I opened up the crown a bit and then wore it at the Texas State SASS match last May when I was trying to do an early 1860's Texican character, complete with my hand made botas, Henry, '58 Remies in Slim Jims, big roweled spurs, red padre beads and Rio Grande Camp knife spear point bowie. It's pretty soft but not floppy (yet!) I don't know if the dimensions are really period correct for that time/place, but living in a very hot/bright climate, I prefer as much shade as possible! If I were to do an 1850's Texican, I'd go with this hat as well.
(The brown spot of the right side of the hat is a nipple pick stuck in the hat band; handy place to keep it!)