I haven't been on the ARMA forums for some time now, I find this article interesting since I was one of the "non-traditionalist practitioners from unaffiliated and un-credentialed teachers of JSA eager and enthusiastic to participate", perhaps the only one on the forums to publicly say so in that now ancient thread. Although to be fair I could care less about credibility, I've known for a long time what I have practised is not historically accurate, more so the experience - so I fully understand the desire to get an actual Japanese student, from a lineaged JSA school.
Is there any harm in saying now, publicly, specifically which schools were contacted and refused?
There are definitely JSA who practice with blunt steel, armour both historic and simulated, though finding a koryu that does so to perform on camera will admittedly be quite hard to convince. I'm speculating but you should perhaps have considered starting with gendai, for a fact Toyama Ryu does do this kind of sparing.
http://www.youtube.com/watch?v=D7nUFpznK7E
Again, whom did you contact out of curiosity? You may not have been talking to the right people.