I tried both 12mm and 13mm extra deep (120mm) 3/8 drive sockets. Crank/prop hub extension still stops it reaching the hex. I think I twigged that you need a simple box socket. Going to pick some up from Screwfix. More expense to just get the prop hub off and replace.
Back to the Lidl.
I am also trying to make it sturdy for slope soaring too.
Ailerons are cut down aileron stock to match the average thickness of the wing (5mm) and now covered in film. Carbon rod installed in tailplane. Elevator too is now film covered. Dug out hole in fuselage for 9g servo.
As a footnote: Each year these gliders come out they vary in wing, tailplane shape, colour. You can see that when look at other conversions over the years.