Re: More variables

Mike,
It's certainly possible that certain locomotives never received plows. As I recall from observation and photos, some of the upper mounting brackets to which you refer were welded to the smokebox, some bolted. In either case, adding or removing them during shopping would be relatively simple.
Quite possibly, locomotives frequently used as "road" engines (which would do most switching along the line) might have "regular" pilots. This would allow the brakeman to ride the pilot during switching moves. Riding the front with a snowplow was difficult, if not impossible, depending on the plow. At some point (General Code experts speak up anytime), riding the pilot became a rules violation. I suspect in later years that is one of the reasons that removing the plow in summer became less of an issue.
One always has to remember that, especially in its later years, the narrow-gauge was money-short, antiquated, and remote from Denver management of the Rio Grande. Thus, much improvising, jerry-rigging, and general "bending" of directives, etc. was done to keep the trains rolling. Old narrow-gauge heads I know are quite amused how fans fixate on this-or-that nuance of locomotive appearance, operating practice, or whatever. As one told me, "We were just trying to keep the damn thing running and get home once in a while!"
Hmmmm, if that sounds a lot like the C&TS today, do you suppose that's a coincidence? How about it, Gerald?