Hartzell/Kelly/Hartzell E-drive starter failed - parts supplier?

[Bluebeard]

After some 7 years/700 flights my Kelly (now Hartzell) ERZ-8012 starter has stopped working properly. The electric motor end is fine and whirrs away but the unit while sending the pinion forward is unable to rotate the propeller for some reason. So I took the assembly out of its case. Just forward of the starter's own solenoid is a clip, just forward of that there is a little spring wire protruding and it looks like it should not be there, something internally has got disrupted and pushed a bit of thin (less than 20 thou) spring
wire out. This is the only bit of external evidence I can see, without dis-assembly of the whole driven end of the unit.

I could probably take the whole thing apart, but are spare parts are available for these units? I can't see anything online that looks like individual components, nor any parts supplier.

I can't find a parts diagram either, to show how the whole thing goes together.

A service life of 700 starts is not very good .....