Thank you John, David and Andy for your helpful contributions. I'm following up on all of them - and yes, David, I'd really appreciate details of the two Australian sources you mention. I've already spent many hours trawling the net but didn't look in detail so close to home - why not I can't imagine.
An area in the book of particular interest (and some delicacy) I think, is getting readers to get to know and understand Christopher (character) on his own terms and in his own world ... C is gradually revealed as special needs but nowhere is it blatantly stated that he is autistic or has Asperger's Syndrome. Readers compile the clues from the outset, of course, unravelling C much as he's unravelling the various mysteries in his life. I want my students to be detective in C's life, so I don't want to hand them solutions on a plate but I do want to handle this critical junction of teaching and reading practice with a deft hand and not spend a disproportionate amound of time on it.
Thank heavens we can edit these posts - I'm still not entirely happy with how I've put the above - but I'm confident you will understand.
I'll post again when I have something more concrete to contribute!
Thanks again to all.