Goblins of the underground kingdom keep in touch with goblins near Flame Altar. The book says Dragonbone Grinder holds the golden key mold.
Use caution, though; these aren't your everyday Goblins. They have some very advanced armor. Waraean looked at photos in the book, concerned.
If the book's right, you can find the key mold near Flame Altar. It'll be much safer if you take a friend.
My soldiers just reported back. Meatbone Goblin has indeed been sighted near the Flame Altar.
Be careful, I hear the Meatbone Goblin, Roguegob, is a vicious one. He especially hates it when you make fun of his name. He'll make it tough to get that key mold.