There are several references to Sherlock Holmes in this movie. One of them is that the "bad guy" is named Lord Rathbone. Basil Rathbone was one of the first actors to play Sherlock Holmes in a movie.
When Artie Doyle tries to break the lock of Madame Tussaud's, Roy compares his work to that of a surgeon. This is probably a reference to the fact that the real Sir Arthur Conan Doyle was a physician, even though in the movie he's a detective.
This movie marks the first on-screen battle between Jackie Chan and Donnie Yen, who have had success in Hong Kong, but had never fought each other before on-screen.
Lord Rathbone in the movie is referred to as "the finest swordsman in England". Basil Rathbone was the star of many swashbuckler movies, and was considered the finest swordsman on the silver screen.
Fann Wong (Chon Lin) trained for her stunts despite not having a martial arts background. She has a background in ballet, which helped to a certain extent.