The pictures of DK Isle and the Giraffes look finalized, maybe the world entrances in DK64 originally had something to do with portraits like Banjo-Kazooie, I mean it wasn't uncommon for platformers on the N64. Also, maybe the giraffe was a beta character, perhaps from a beta world that wasn't put in the game, unless someone can tell where that picture of the giraffes was taken..? Anyways really awesome Rune, and it would be awesome if you could take a screenshot of that giraffe picture and upload it, if only because it looks nice.
EDIT: Just had another thought, maybe the barrels that let you change characters were originally themed with their levels as different objects. The stump would be from Fungi Forest (obviously, since that's where you found it
)