The "V for victory" matchbooks were for war bonds and were not fictional.
The dubbed German version released in 1959 removed all Nazi references from the dialogue. The story of this edited version is about gangsters trying to get hold of a secret medicine formula that could be dangerous if in the wrong hands.
Clarence Muse plays the part of "George" the porter/barman. During this time, many black rail way servants were called "George" by their customers as a generic name that is easy to remember. The senator tells "George" to bring him a drink.
Uniquely, Holmes and Watson do not appear until the second reel of the film.
George Zucco and Henry Daniell both play villains in the film. Zucco earlier played Professor Moriarty in The Adventures of Sherlock Holmes (1939) and Daniell later played Moriarty in The Woman in Green (1945).