Braun Stick Mixer Coupling 4191

The mechanical coupling between the motor and attachment on our Braun stick mixer broke.
A replacement part seems to be available on ebay, but it works out at a large fraction of the price of the mixer!

My hopes were raised when I saw http://www.thingiverse.com/thing:112547 http://www.thingiverse.com/thing:633453 and http://www.thingiverse.com/thing:1019768 but unfortunately the coupling on our mixer is different so I modelled it up in openscad. This printed version fits nicely, we'll see ho