There is no "Startup Disc manual", at least not one that any customer would have. There were probably instructions for it for the retail kiosk people, however. There might be a variant of the Wii manual with Startup Disc stuff in it, which is what I'm looking for, but it's not a "Startup Disc manual" per se.
Personally, I would only consider it "found" if the actual disc was found, because otherwise there's no way to tell if the found remnants are all that comprise the disc's content. I'd call it "partially found" or, if you're confident enough that most of the content is there, "partially lost".
Thats what i said, maybe we should put it under 'partially found' if we got some assets of it and not the whole disc
