Squishy, Hemingway's 'The Old Man & the Sea' is one of my most favourite books ever. I re-read it recently. It's stunning how well he writes. DS tried 'The Book Thief', but didn't click with it. That was over a year ago though, so worth trying again.
Bonus he's taken against 'Lord of the Flies', I think because it was on a school reading list. Your Mr Jones sounds quite a character..!
The 'Catch 22' thing is interesting. I'll have to give it another go, but I think on balance 12 is a bit young, so I'm not going to get that one for him just yet. It will be interesting to see if he finds it in the library himself. 
The basic problem is that he wants to find things himself - which is a good instinct, but means I suggest something he's far less likely to go for it. We have walls of books at home, so he has a lot to choose from.
Bertrand that's a great list thanks and we have most of those here, so I will dig them out. What's the 'mum pile'? Is that you putting a bunch of things together that you think your DS might like? I might get away with that so long as I don't babble on about them too much.
Thanks all for the suggestions. I'm keeping a list. 