I just posted this over in the Ruby Slippers thread, but it fits here, so *copy paste*….
I sorta hope that the Wizard of Oz is only the Wizard of Oz, and not also Frankenstein, but now that I think about it, it could work. We didn’t see Jefferson go to get Victor in this ep. We saw Jefferson happen to run into Regina at just the right time to offer to hook her up with Victor, but later, it turned out that the whole thing was a setup by Rumple to turn Regina into a monster. Maybe Rumple had sent Jefferson to Oz with a shopping list: crystal ball, magical slippers, Wizard. And he brought back 2 out of the 3, though in that initial scene, he was only seen to hand over 1, because it was all part of the ruse to corrupt Regina.