I don’t think any of these have been mentioned before, and I don’t think they have been televised or filmed:
The Voyage of QV66 by Penelope Lively deserves to be far better known and is a wonderful adventure story and clever allegory;
Edward Eager’s Half Magic, Magic by the Lake, The Time Garden, Knights Castle, Magic or Not?, The Well Wishers, Seven Day Magic;
E Nesbit’s The Story of the Treasure Seekers, The Wouldbegoods, The New Treasure Seekers, Harding’s Luck, The House of Arden, The Wonderful Garden, The Story of the Amulet, Five of Us and Madeline, The Magic City, Wet Magic;
When Hitler Stole Pink Rabbit by Judith Kerr;
Noel Streatfeild’s The Growing Summer, The Circus is Coming;
Philippa Pearce’s A Dog So Small, Minnow on the Say;
Gobbolino the Witch’s Cat by Ursula Moray Williams;
Cynthia Harnett’s historical novels for children;
Nina Beechcroft’s Cold Christmas, Under the Enchanter, Well Met by Witchlight, A Visit to Folly Castle.