Try looking at the Anthology of 20th Century Piano Music. It is edited by Maurice Hinson and published by Alfred. If nothing else, you could find it online and get some titles of pieces.
I'm not acquainted with the British system, what other pieces are grade 6-7 students playing?
Gyorgy Kurtag's Jatekok (Games) should work. They are usually one page and lots of squiggly lines.