It appears a real bottle of Old Grand Dad bourbon whiskey - 100 proof "Bottled in Bond" - is found in the back seat of Johnson's ca when he's out "parking" with Anne. Unusual product placement during Prohibition. Other such bottles can be seen throughout the film. It was allowed to be distilled under strict government control during Prohibition for "medicinal purposes".
Late in the movie when Jerry (Russell Hopton) shows Cagney his money-making scam of selling "swastika charms" there is an abrupt edit, probably a close-up of what the charm looked like. Swastikas had been considered good-luck charms until the advent of the Nazis two years after this movie was released, and the edit almost certainly took place between then and 1941 when other war-related edits took place in Hollywood (e.g., anything relating to Italy in the Marx Brothers' A Night At The Opera).
This film's earliest documented telecasts took place in Indianapolis Monday 29 July 1957 on WFBM (Channel 6), in Tucson Friday 9 August 1957 on KGUN (Channel 9), and in Portland, Oregon 27 August 1957 on KOIN (Channel 6). For the past 60 years, it's since been a frequent flyer, first on local television, then on cable, and has now found what is apparently its permanent home on Turner Classic Movies.