I've been wondering this for quite some time, but there seems to be very little information on the topic.
I own Barrie's novel and have read the play online, both released by Project Gutenberg. I am unsure of the publishing dates, but I believe the novel was published before the play.
In Barrie's novel, Hook's dying words are "Bad form" whereas in the play, his dying words are "Floreat Etona!" ("May Eton flourish"), (and in "Anon: A Play", Hook doesn't appear to have any last words whatsoever). I, being particularly interested in Hook's rather shadowy character and past, wonder why Barrie chose to change the quote in the novel, or vica versa. I suspect it may have something to do with the Davis boys attending Eton, but I'm quite unsure. What do you guys think? Is there any info on this online?