Greg,
Not to step on your toes or start a flame war (I too enjoy seeing stuff lettered for its real parent railroad and not a tourist line or silly made up name that supposedly the tourists will find cute, etc.) but, when does the tourist line's name stop being non-authentic, and in its own right, become a legitimate historical lettering style?
For example, how long has the current Durango & Silverton lettering scheme been in use? 25-27 years? Compare that to each of the Rio Grande lettering schemes. The D&S lettering may have lasted longer than some of the lettering schemes used by the Rio Grande.
My point is, at some point, after so many years of use, the name and lettering style of the tourist railroad becomes historic in its own right.
Just a thought.