Actually, the episode you insist on referring to as "Inventors Hall of Fame, Part 2" is titled just "Inventors" on the DVD set. Furthermore, despite airing as the 24th episode, "Inventors" is actually the show's first episode in production order, which really messes up the alternate name.
I'm all for covering multi-part episodes like "Hooray for North Hollywood" or "Brainwashed" in one article, but I feel Histeria! is an exception in that regard, because it didn't really do multi-parters the way most shows do. The "Part 2" episodes don't directly follow the "Part 1" episodes in airing or production order, and since the show is a sketch comedy, there's really no arc between the episodes.