These are great! I see from the Daily Tie-Up Report from December of 1916 that the 40, 41 and 42 were still lettered and referred to as 402, 409 and 420, respectively. Also interesting is one of the last usages of engine 18, which was scrapped 12-31-16. Actually, I believe all the engines which had not been reboilered had to be off the roster before 1-1-17 so she may not have been 'worn out' in the strictest sense.
Also, I love that telegram from October 12, 1916 about the cattle at Pine Ridge. Any bets some stock cars were wrecked out there a day or two before and the cargo was on the mooooove?