Some luck...

I found a site backup from 2006 with every post from Sept 30 2004 to June 6 2005, so the old board was still running then. The request Board goes back to Sept 29, 2003 and The Misc. Board to Nov 25, 2003. I suspect that's the oldest backup I have.

I tried using the internet archive wayback machine and it goes back until June 2003, which must have been when the aforementioned upgrade occurred. So I'm more interested to know if you have any old posts from ~2000-2003?