....The Man Who Shot Liberty Valance to that list. I watched it, followed by The Shootist.
My 2 favorite old western actors are John Wayne, and James Stewart. As I understand it, these were the only 2 movies these iconic actors shared screentime on. I believe they were both in How The West Was Won, but they did not appear together, and Waynes part wasn't much more than a cameo appearance anyways.
Anyways... that's a good list, I've seen them all, some several times over. Can't get enough of the classic cowboy movies.