This leather-bound, gilt-edged edition of Leroux's novel was published after the musical's success but is now very rare and expensive. I don't own a copy and have never even seen one in person, so I do not know if there are more illustrations included than the plates below or not, but these few I have are worthwhile to be shared.
Inside the front cover: Masquerade.
The key to the Rue Scribe gate.