"THE SUBTLE KNIFE (Scholastic Children's Books, London, 1997): Signed by the author on the full title page. The correct numbering sequence of "2 4 6 8 10 9 7 5 3 1" is present on the copyright page as required for the first state."
In the absence of further research, I would say that you most likely have hit the jackpot here."

Uh, no, going by this quote here you would need the full number line for the first state, and therefore for the "jackpot". In all likelihood this was a 2nd print run where the number 2 was omitted in error.