Interesting set of visuals you bring into play here. The movies all do seem to have the values of the "Knight Errant" in them once you think about it. Since I can only remember four of the titles right off the top of my head, would you say that "The Shootist" and/or "Enter the Dragon" might be two of the other films that could be on the list? I ask mainly because both seem to have main characters with similar qualities as the ones in the movies that were listed.
Rob