I found a 1941-ish newspaper article and photo of 71 in the Denver yard.I have larger scans on my site.
"Colorado & Southern locomotive No. 71 puffed up to Blackhawk and Central City when mining fortunes were being taken from the ground and the maintain camps swarmed with gold seekers."
"The stubby, narrow-gauge locomotive will make its last trip today, but not under its own power. It will be towed up to Central City as a monument of the old days.
"The train will be manned on its last trip by J. W. Caraghar, engineer; Martin Garrity, fireman; T.D. Brown, conductor, and David Duggan, Sam Griffin and Frank Weller, brakemen.
This fell out of a copy of "Narrow Gauge in the Rockies" I acquired. No date on it. But the reverse of this clipping talks about "If the Germans succeed in their campaign against Greece and Yugoslavia..", so early to mid 1941 I think?
-Nick