Warren,
Most of the TAG photos are shown as being from the Garreth M. McDonald Collection. Some are from William B. Gwaltney, Kenneth Ardinger, Emery J. Gulash, and Robert F. Wilt. I ordered my book from Morning Sun at the Pre-publication price of $59.95.
The Chattanooga Traction section is small. One page of history and five locomotive photos, two of which are former CTC #3 as Ware Shoals Railroad 1955 and CTC#4 in Southern/CTC paint scheme but actually recently taken on the Knoxville & Holston River Railroad.?
The sad news is that on the Trainorders' website there was a recent post containing an email that an author received from Morning Sun which stated that they were going out of the printing business and that no new books would be published after 2024. There was a possibility that digital books might be available after that but that was not a sure thing and more details would follow.
Charlie