I found the stamp on the front derailer, and it's XG. According to the site, at least that part was made in Jul of '99.
The only code I can fine on the rear is RD-M510. As far as the specialized website, they archive back to 2002. The low end Rockhopper they have for that model year looked similar to this one, so that is why I was guessing '00 - '01.