Visitors from London by Kitty Barne is out of print and copies currently sell for £50 and more on abebooks.co.uk. As I have a self-imposed limit of maximum £15 per book, I’ve not read this yet.
According to Keith Barker in Outstanding Books for Children and Young People – the LA Guide to Carnegie/Greenaway Winners 1937-1997, this book has dated and was the first Carnegie Medal winner to go out of print. However, Cheri Loyd provides a spirited defence of it in Out of the Attic – Some Neglected Children’s Authors of the Twentieth Century so I will definitely seek it out when The British Library opens up again!
Mette Reads Carnegie 