After reading some in some old topics on the board I've achieved quite useful information.
The BIG.Z folder does contain models, but they are not that useful for us who wants to mod the game. If you changed the Qui-Gon model to the Jar-Jar model (for example), the game would probably crash - because the Jar-Jar model doesn't have the same animations like the Qui-Gon model.
Since the company Big Ape doesn't exist anymore, I don't think Zanzibar use the firstname.lastname@example.org
mail these days, since it was his job mail. Our only chance for real contact would be if we could get his personal mail somehow.
If we could get in touch with the guy, we must keep in mind that it's one HELLUVA chance that he doesn't own the source files anymore. Well, you never know... maybe they are saved somewhere...