I remember reading Dolphin Island by Arthur C Clarke somewhere around then, a good first Clarke book. Also Two Against the North (also called Lost in the Barrens) by Farley Mowat, an adventure story also. And then Stevenson, if he hasn't read Treasure Island that is a classic pirate tale, if he liked Treasure Island then Kidnapped.
I had a Agatha Christie year and also a spy year (every single Ian Fleming book) but I can't remember what years those were and whether the Ian Fleming books would be appropriate yet.
Polly
