Why Ke-Ni? Because it is rare. Everyone has Sherman or Panther but WWII Japanese armor mostly unknown.
So what I have now - pics from original manual, simple plan of unknown origin, few poor photos and renders from World of Tanks (WOT model is not accurate enough).

And now project started:

Hull is empty with 1mm thick walls to reduce volume and make print cheaper.

Next episode is hatches, rivets and other small details.