However, you can try these resources:
* Film Archives: Contact film archives like the Cineteca Nazionale in Rome or the British Film Institute (BFI) in London. They might have information about the film's cast.
* Film History Books: Look for books and articles about Italian silent films and the career of Bartolomeo Pagano (the director). They might include cast lists.
* Specialized Film Databases: Search for "Maciste sonnambulo" in specialized databases that focus on historical films, but be aware that these databases may not always include older films.
Good luck with your search!