That's a beautiful quilt, Fiona!
If the fabrics were mine, I would find a pattern that highlighted different combinations of 2 or 3 of them, like a Dresden. Or maybe a repeated applique like "dancing umbrellas." I've done a graduated pattern before, and it was surprising how differences in value and delicacy caused all kinds of trouble that wasn't obvious when they were in one delicious group.
Hugs,
Charlotte