WOW! To put it mildly. I have always considered the Rocky Mountain Railroad Club books (DSP&P, Rails Around Gold Hill, Colorado Midland, Pictorial Supplement to DSP&P, and the Memorial Edition of DSP&P) to be the Gold Standard of railroad books, but this one is, I believe, a level or two above them.
Of course the technical side of photography and printing in the 40s and 50s wasn't nearly as advanced as it is now. but.....
Wonderful book. Heartiest congratulations to those who put it together and still found time to work on 315 itself.
Ed