Finally finished it today, but during it's production it's grown, much closer to 43cm now.
I'm still playing with Keefs straps to get a good comfy fit, but this is very close.
I've twisted the front straps to conform to the shape of my feet, trouble is this tends to narrow the entry a bit, should have spaced the plugs a tad wider apart.

Just noticed in the pics, it looks like I have the front of the front straps in different holes, have to check that tomorrow.









All I need now is some wind to test it out.