I am a first cousin, 4x removed, of Wm Conway Whittle, Jr and have two photos that I believeare post-war photos of him. One, with a date of either "Jan 1869" or "June 1869" (hard to tell...) penciled on it, has a mustache added to the photo. Photo studio: Richard Walzl's "Palace of Photography", Baltimore. The other has "For cousin Toka [Matoaka Whittle]" written on the back. She was my great-great-grandmother and his first cousin.
I'm comparing them with a photo of him in uniform that has shown up in several places on the web.