There were a few AP exclusive Haunted Mansion items. A wooden tray, a tank and a tee shirt. Not sure if they are still available. There's also AP MVMCP ornament and tee shirt in addition to the pin.
Not necessarily every park, but often "events" will have AP merch. So the festivals at Epcot, parties at MK, new rides/lands stuff like that. It may just be a pin, or sometimes it's a few different items.
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