Back to back with Parent Trap
Based on film history MO and BK filmed DC and Parent Trap back to back in 1961.
Couldn't have spent much more time together in 1961 if they had been married!!!
THE DEADLY COMPANIONS exists, and became Sam Peckinpah's feature-film debut, because of THE PARENT TRAP.
O'Hara and her brother, Charles FitzSimons, formed a production company to make their low-budget Western project, with FitzSimons as producer. She wanted Brian Keith for her co-star in COMPANIONS because of how much she had just enjoyed working with him on the Disney film.
But Keith and Peckinpah themselves had loved collaborating on their all-too-brief, low-rated 1960 TV series THE WESTERNER (canceled after only 13 episodes but still admired to this day), and they became good friends. While drinking together one evening, the two men promised each other that whichever one of them got offered a movie first would try to get the other aboard, too. When O'Hara contacted him about DEADLY COMPANIONS, Keith asked whether they had a director yet -- and then kept his word to Peckinpah by selling O'Hara and her brother on the talented young guy with whom he had just done a Western TV series. Nobody had a good time making the film; but Peckinpah made his way toward his destiny.
Now that COMPANIONS finally can be seen again fully letterboxed on Turner Classic Movies and on DVD, more viewers are discovering that this debut film is better than the secondhand reputation it suffered for years.
Most great films deserve a more appreciative audience than they get.