I am in the process of restoring this live-steam model of the C&S #22, so I too have been looking for books with photos & info on the Colorado & Southern. In addition to the books previously given I would suggest these.
Narrow Gauge Pictorial Volume VI - Motive Power of the Colorado & Southern by George L. Coleman There are lots of great pics of C&S locos including my #22
Goin' Railroading, A Century on the Colorado High Iron - by Sam Speas as told to his daughter Margaret Coel This is a fascinating story of work & life on the narrow gauge RRs with many photos.
Silver Rails, the Railroads of Leadville, Colorado - by Christorpher James James carefully researched work gives much insight into the many railroads, including the C&S, that served Leadville, their failures & mergers.
Finally, Jason Midyette modestly omitted his recent work, One Short Season, Colorado & Southern #9 Jason has many photos & much history on the #9 on the C&S
I hopes this helps. Please let me know if you find more on #22.
Steve