Right, I know. But it's more complete that way I guess.
Here's more to add some to the discussion.
In German but they built their own driven nut.
http://cnc.a-ueberbach.de/tag/angetriebene-mutter/
And here you can buy a complete drive or parts for any size ballnut.
https://team-haase-shop.de/maschinenelemente.html