I had never heard of the American author Paul Gallico (1897-1967), but book websites do what they're supposed to, so this ended up in my recommendations. The Snow Goose (1941) is a very endearing novella about a hunchbacked man living a lonely life in an old lighthouse on the Essex coast, UK. There's a snow goose involved, of course, and a young girl, but the plot revolves around the spectacular relief of British troops on the beaches of Dunkirk, France, in June 1940. The narrative is very classical, with a restrained yet dramatic tone. Gallico verges on melodrama, but in my opinion, manages to avoid that pitfall. Beautiful.
The other, shorter novella, The Small Miracle (1951), is equally endearing, but because a young boy and his donkey are the main characters, it's considerably more sentimental. Nice, though.