The airplane shown as taking Lucky and Iris on their honeymoon is a 1933 Boeing 247D, registration NC13334, flown by United Airlines. It crashed in Bethel, Connecticut on 30 May 1934 on a flight from Chicago to Newark, New Jersey, via Cleveland, Ohio when it ran out of fuel in bad weather. All nine passengers and three crew members survived. The heavily damaged plane was crated up and hauled away by United. It was rebuilt as a 247D model and resumed service for the airline in 1935. It was subsequently sold to the Colombian airline SCADTA and was still flying in 1945. Its fate is unknown.
Ronnie's $30,000 gambling debt would be over $635,000 in 2022.
When Fishcake is talking to the French proprietor of the salon, he says he was in the "AEF" - which audiences at the time would have known that stood for the American Expeditionary Force in WWI.
Quick walk-ons by Ward Bond as Lucky's henchman and Dennis O'Keefe as the rich Ronnie's side kick. Both uncredited.