(does anyone else remember the glory of going to the book fair? Books, books, an entire room in the school suddenly filled with shiny new books)

Yes, indeed. I remember us having a couple of book fairs at primary school. (I bought my first Chalet School book there, and also a 2p copy of Charlotte's Web.)

Like most of the Caldicott winners, I hadn't heard of this one, but Googling the images is also pretty delightful - I can see why it won, and it sounds like a lovely picture book to have had amongst your collection. There's some really beautiful and effective work in there.