Ethan,
A quick trip to Dirty Billy's website shows he still carries the US-29 1861 Whipple hat for $195. That sounds pretty expensive but with the added details requiring more labor, the price isn't so bad as it first seems. Per our original discussion, though--it is a time limited bit of kit for the Sharpshooters.
There were a few of the Ohio USSS (Co. A 1st USSS) back in the mid-late 1990's that purchased and wore the Whipple hats for their regional events and a few showed up for the 135th Antietam. I nearly shot one Buckeye recruit (wearing a Whipple), retreating thru the dense corn and smog thinking, he was one of Hood's boys coming to finish me off. I had just got 'whacked' as regimental color bearer and Adjt. Parmalee (Randy Bartley) grabbed my flag and disappeared into the gloom with the survivors of the regiment in hot pursuit. One memorable and crazy scrap--and easy to see how the orders to the Sharpshooters to turn in their gray overcoats and Whipple caps were both timely and apropos.
http://www.dirtybillyshats.com/It is possible one of those Ohio fellows might have a Whipple moldering at the bottom of their USSS tote--but I suspect most were sold off during the intervening years. However, if I hear of one 'still out there' I'll let you know. Good luck with your search.
Bill Skillman
Hudson Squad Mess-USSS