Sweet score! You should see if xwhatsit is interested in trying to adapt his IBM beamspring/Model F capsense controller for these boards. It might only cost you one board plus shipping to New Zealand if he's interested.
DPH capsense should be able to handle it as well.
---
hardened cases: The only military hardened KB is the one I brought to keycon. From what I read there's three levels:
1 : commercial grade stuff
2: somewhat hardened (mine is this)
3: very hardened.
My KB is in a well-grounded case of welded magnesium. It's pretty awesome. Something similar should be of sufficient quality for these boards.