Hildy reminds Jenny, the cleaning woman, that he got her husband on "The Amateur Hour." Major Bowes' Amateur Hour premiered as a local show in New York in 1934 and on the NBC Network in 1935, six years after this movie was set.
When Hildy enters the press room to say goodbye to his fellow reporters, he greets them with a Edward G. Robinson imitation, saying "This is a raid, see." Edward G. Robinson would not become a famous enough to imitate as a "gangster" until Little Caesar came out two years later.
Walter Burns visits a Balaban-Katz theater while it is showing a Universal Newsreel. Universal distributed this film but the Balaban-Katz chain was controlled by Paramount and would have shown the Paramount Newsreel. In addition, at the time this film was set, Universal distributed Hearst's International Newsreel. The Universal Newsreel was first seen in August, 1929.
The Movie supposedly showing at the Balaban-Katz was the Silent The Phantom of The Opera, a movie that came out in 1925. Since the story takes place in 1929, it would have been unlikely that a 4 year old movie would be in a first-run theater. Furthermore, a Silent showing in a first run movie palace would have been unlikely in 1929 - almost everything were "Talkies" by then. Finally, if a Silent were for some reason playing, Peggy Grant wouldn't have stepped away from the organ console after "Button Up Your Overcoat." After the Newsreel she would have gotten down to business accompanying the Phantom.