Google has a 'captcha' on Google Groups which prevents mass copying. There is a guy with those tapes, but they're the early 80s - I don't know where Dejanews got their original archives. But that guy would be a start.
When I had a Giganews account I looked at how far back their text groups went, and I think they went back to 2003, but that was a couple of years ago. Might be worth looking at EasyNews or Giganews, at least for more recent history.
