Since the book referenced is only a preview and doesn't show the photo in question in detail I ran upstairs and pulled it from the shelf. (The joy of working at a university library) The caption with the photo suggests that the Home Guard were at least partially equipped with cavalry gear. This book does give misleading information; in the caption by the photo of Zeke Proctor from early in the war it mentions his later photo in a dark sack coat, like many Confederate Indians, but fails to mention that he had joined the 3rd IHG. So, they may be confused about the armament of the individual in the questioned photo.