Fear not, it's nothing bad...just annoying.
About a week ago I contacted Nintendo about legal and copyright stuff regarding Perfect Dark and the mod (I had already tried and failed to find a contact e-mail address for Rare Ware). They told me to seek out Rare as they own the copyrights to the game.
While I'm sure this is nothing to worry about (as Perfect Dark is three years old), I thought I should let everybody know. Seeing as how I can't EXACTLY duplicate the maps, we should be safe there. And since it's virtually impossible to EXACTLY copy every aspect of gameplay, no worries.