I also have a copy of the book. My great grandfather, Joseph Lemule Mewborn and his two brothers, Joshua Wilson and James Charlton joined the 13th Tn volunteers, Co. B from Macon, Tn.
Joseph was captured after Chicamauga and spent the rest of the war at Johnson's Island. His two brothers also survived the war and lived to be old men. They participated in the Great Snowball Fight at Dalton, GA while wintering over. I have copies of Joshua's memoirs of that incident somewhere. Your relative probably was there, too.
Listed in the roster was a black slave also named Mewborn who accompanied the three brothers to war.
I would like to get my hands on a photo of the regimental flag, or of any men of the 13th in uniform.