We traded at Frontier Trading Post in MK, Mouse Gear in Epcot, and I believe it was Island Mercantile in Animal Kingdom. It seems they are down to one store per park for trading. We didn't trade in Hollywood Studios.
The Trading Post in Frontierland at Magic Kingdom, Mouse Gear and Disney Traders at Epcot, Villains in Vogue at Hollywood Studios, Island Mercantile at Animal Kingdom, and DStreet at Downtown Disney.