There’s a children’s book (supposedly a boys’ adventure story) I loved so much, I found a 2nd hand copy online, since the original was getting a bit dog-eared. And one more for a sibling!
It’s entitled Chalky, by Howard L Apps, published in the 50s and set in that era, but doesn’t really read ‘dated’. Very funny in places, it’s the story of two very ordinary boys who go in search of a very valuable diamond, lost many years ago by a now-poor and reclusive old lady neighbour.
The search takes them into the Essex marshes and into real danger.
It’s a cracking read - I still revisit it now and then!
Nobody else ever seems to have heard of it, but IMO it would have made a brilliant film.