Probably not, because he has so many fans writing into him they won't be directly signed by him, they will be all computerised autographs. When I wrote to J.K. Rowling she couldn't send me anything because of the ammount of fan mail she gets. It's impossible. You can try though! Good luck! X
You can send the cover of the book or something to the place where he dives in plymouth and give an extra stamp and envelope so he can send it back, I asked someone who got fanmail back what she did and she said this so i assume you can
