The Couplemate website is pretty good for info.
http://www.couplemate.com.au/index.html?ext262.html&1
Interestngly they sell ALKO gear but no mention of the electric turnback. In fact if you look at their stub axles they look the same as what I have.
ALKO is at Underwood though so I will probably just go there once I have decided on what to get.
It is annoying though that wherever you look or whoever you talk to they never seem to have the full info. They are always unsure. The Couplemate site seems to show that it is actually quite straight forward.

