Hello Sandman, here the measurements:

shaft length (from ball bearing to the end) : 57mm
thread length : 17mm
shaft diameter : 10mm
thread : M10 x 1

I think that You can get the two spanners, one with inner tapper and one with outer tapper, from Mr. Seidel, so that You don't have to make a tappered hole with the correct angle inside the hub, a cylindrical hole for the spanner with the inner tapper can be made much easyer. As the ST710 shaft is 10mm shorter, You probably can make the hub thicker.

gnome

Holm und Rippenbruch