Great Western Railway

Some of you folks in Colorado might be able to help me. Looking for some info on this Colorado Short line in steam days.

(1) Is this map pretty much the same as say in 1959?
[omnitrax.com]

(2) Where was the majority of freight interchanged with either C&S, or UP?

(3) Were the steam engines used year round, or only during the beet harvest season?

(4) I see where #90 was built in 1924, but could not find out when it was sold to Strasburg?

(5) When were the engines retired from active freight service on the Great Western

(5A) When was the last steam excursion operated(Last steam on the GW), and which engine.

Thanks,
Greg Scholl
[www.gregschollvideo.com]