On the IMDB page for the tv special 'Make Up- Bishoujo Senshi Sailormoon' (http://www.imdb.com/title/tt0392387/) the cast list includes Naoko Takeuchi as herself.

I didn't see her in the show though, and wondered if anyone could point her out.
I posted this on the IMDB boards but as they are pretty much dead, I though I would ask you lot here.

Ok..Naoko appears with the senshis before the conference in Yokohama... :D