Based on a "Richard Diamond" radio program with the same title.
Hope Summers and Howard McNear though not in any scenes together were both in The Andy Griffith Show a few years later.
In the coroner's office, talk of 1830s guns and a rifle made to kill Louis Phillipe. Peter gives an odd shrug and sternly says, "OK, Louis. Drop the gun." Only he is amused. Back then a lot of folks believed that Humphrey Bogart, in Casablanca, had said "Drop the gun Louis". He hadn't.
Hope Summers and Howard McNear would later play reoccurring characters in The Andy Griffith Show.
At 00:52, the car's license plate does not have the name of the issuing state. Neither does the plate on Peter Gunn's convertible at 12:00.