My Son, the Hero (1943) is one of those Apple Annie stories: small-time grifter Big-Time Morgan has been telling his son that he is a successful business man, and has to fake up a mansion, wife, etc, when he comes to visit. It's been done a thousand times. The sweet part is who plays Big-Time and the rest.
Big-Time is Roscoe Karnes, the classic wise-cracking character actor. He is the agent of a glass-jawed boxer, played by Slapsie Maxie Rosenbloom, the classic punch-drunk slugger. Maxie's ex-wife is brassy loud-mouth Patsy Kelly, with everybody's favorite Italian stereotype Luis Alberni filling out the cast of characters.
If you don't know who these people are, try this one out. I think you'll like them. Karnes, often a cabbie or hard-bitten reporter, gets to show a lot of soul here. He is a grifter and out of control gambler who always loses, but he loves his son and can't bear to disappoint him. Kelly doesn't have a big role (even though she's top-billed) and tones down her act a bit, which makes her easier to like.
The rest of the cast are the straights - Karnes' son, who is a war correspondent trying to sell a lot of war bonds (which is like a con job, but for the government). He falls for a show girl hired to play his half-sister, although there is a nasty rival for his affections.
That part of the story is really skated over. The straight world isn't really for them. This is Roscoe's movie, with Patsy, Luis and especially Slapsie Maxie.