Yeah, I didn't know that story and frankly I didn't remember anything about that hamburger chain. It seems like they got out at the right time.Key Largo. I can't believe I haven't seen this film before (or don't remember from perhaps a 60s TV viewing). Top notch writing, directing and acting all around. Robinson and Trevor are definitely the stand outs, but don't forget Barrymore. His helplessness and despair in the wake of Rocco was heartbreaking and palpable, and when also he's told the Osceolas were dead.
The fun Muller comment was the bit actor who went on to invest $5,000 to start Hamburger Hamlet, which later sold in 1987 for $33 Million. I contributed to that fund having many meetings with my agent at the Hamlet on Sunset right at Doheny in the 80s before it sold. That was the business lunch location. There also was one right on Hollywood Boulevard across from the Chinese Theater. That was the tourist mecca location. Location location location.
https://www.latimes.com/local/obituaries/la-me-marilyn-lewis-20170505-story.html