Wow… I think you may have nailed it. I also saw Tin Man’s oil can on one of Gold’s shelves in episode 1×16 Heart of Darkness. No way he’s Pinocchio, you’re right about that. That would be such a let down (even if he was Bae). Peter Pan would be exciting. But you have nice evidence to back it up.
So do you think he had anything to do with bringing Henry to SB for Regina? Do you think him and Rumps made a deal back in the day and maybe August tries to kill him instead of honoring that agreement?
Being Oz would also explain how he knows so much. And, like Oz helped Dorothy get back home to Kansas, August is helping them get back to where they belong.