Well I would see if you can find any images of 29th Wis infantry soldiers in uniform and base it of that. It would most likely be a forage cap and or a slouch hat being a from a western theater unit. Once you get that sorted you can see what Dirty Billy from Gettysburg has or check Greg Starbuck on Facebook, his site is called Kepi Nation on Facebook. I have a few dirty Billy caps and I am still trying to justify one by Greg Starbuck. I only have one head and can only wear one at a time....