Others are partially available. I trust you can figure out how to find them!
Interested in helping out with this project? The most useful thing you could do would be to find people you know on the list of copyright holders at http://wiki.mnstf.org/index.php?title=MinDocDigPro#People_who_have_given_no_answer and ask them:
"Is it ok with you for Minn-stf to redistribute your contributions to Minicon publications as we like? Or alternatively, would you allow us to redistribute them under some restrictions you name? (We're very flexible.)"
Or something to that effect.