After reading the episode description for episode 20, I also think that August is Pinocchio. The fact that Geppetto searches for a way to save his own child at the same time he agrees to help save baby Emma fits the theory that it was Pinocchio who also got transported to our world as a 7-year-old boy and turned in the baby to police. I think the writers have been toying with us by putting the episode with Bae and Rumple (The Return) back to back with the next episode featuring Pinocchio called The Stranger. I still think Bae could be Peter Pan or a Lost Boy, but we won't see his back-story until season 2. Also, I think The Return talks about Bae's return to his father in FTL after a brief absence to fight in the Ogre Wars. From other interviews I've read by Robert Carlyle, we'll only see Bae in FTL, not SB.
"That’s how you know you’ve really got a home. When you leave it, there’s this feeling that you can’t shake. You just miss it." Neal Cassidy