I wasn't involved in the community before '03 myself, but I can give you a few pointers that might (hopefully) be helpful:
- On Usenet, aside from the groups mentioned above, there were also a good number of ex-Witnesses in alt.religion.jehovahs-witness
- The WT was giving warnings about BBSes (not necessarily net-connected) back in the early 90's. I've heard some references to Prodigy boards; I don't know about other ones.
- ChannelC, run by Ros/Atlas (Rosalie Hughes), has been around for a while and gets posts from luminaries such as Jim Penton, Carl Jonsson, and Rud Persson. Ros is a board member of BRCI (along with--among others--Peter Gregerson, whom you may remember from Crisis of Conscience). She also owns the Beacon site, and manages a couple of listservs.
An interesting footnote to history would be witnesses.net. It was run by an undercover ex-dub, Obie Fernandez, as a 'honeypot'; basically, a genuine dub site, but one where Obie gradually let in other undercover ex-dubs to subtly encourage free thinking. I respect Obed for what he tried to do, although I still don't agree with his methods. Still, the site was in many ways a success; it was far larger than any other dub site since then.