Cast Metal Plate - Mount Zhayolm

Hey folks,

Been trying to do this for 3 days with no luck. I'm trying to do the "Waking the Colossus" quest for Alexander. It is my understanding that I need a "Cast Metal Plate" key item to open the Gates of Halvung to access the area I need to get to so I can finish this quest.

So, I go the Halvung staging point, mount my raptor, go to the closest Gates of Halvung, dismount, touch the door and get a message about a keyhole, mount raptor, refer to the wiki map for ??? spawn locations for the plate, and ride around to the spots. I have not zoned. I make sure when I start and finish this that it's on the same FFXI day. I have never seen any ??? in Mount Zhayolm at all except for the one for PUP AF.

Am I doing something wrong? All I want to do is open the gate.