It's taken me a while, but I can finally fold this, albeit using a non-standard folding method.

It was designed by Ian Chapman-bell. You can get the original diagram from Box of Seven Joys

My own folding method involves dividing the paper into fourteenths using the binary fractions method, cutting the folded fourteenths into a circle, and then following the Ian Chapman-bells' instructions from step 11.

Box of seven joys