Sorry I didn't find you guys sooner. On IMDB you can search by cross-linking two names. Just scroll way down past all the movie credits, and you'll see the Actor'sName & __________ . On the subsequent page, you'll have to select which names and category (actor, director, etc) to cross.

Besides Keenan Wynn and Richard Jaeckel, did anyone consider these actors? Eli Wallach, Lee Marvin, Charles Bronson, Robert Ryan, Ben Johnson, James Coburn, Warren Oates, Cameron Mitchell