Preheat the oven to 300 degrees F. Butter a 3-quart baking dish. Put cubed Cornbread and Italian bread on 2 separate rimmed baking sheets and bake until very dry, about 20 minutes. Let cool and combine in a large bowl. Increase the oven temperature to 375 degrees F.
Meanwhile, cook the sausage in a large skillet over medium heat until nicely browned and the fat has rendered out, 15 to 18 minutes. Transfer the sausage to a paper-towel-lined plate using a slotted spoon. Pour off all but 1 tablespoon of the sausage fat.
Melt 4 tablespoons of the butter in the skillet with the sausage fat. Add the celery and onions and cook, stirring occasionally, until the vegetables are softened, 8 minutes. Stir in the sage, thyme, red pepper flakes, nutmeg and garlic and continue cooking and stirring until the herbs are fragrant, 2 minutes. Pour in the white wine, bring to a simmer, and cook until the liquid is almost completely absorbed, 5 minutes. Remove from the heat.
Melt the remaining 4 tablespoons butter and add to the bread cubes along with the sausage, vegetables, turkey broth, oysters, oyster liquor and eggs. Season with the salt and black pepper and toss to coat.
Spread the dressing mixture into the baking dish and bake, covered with foil, 25 minutes. Remove the foil and continue baking uncovered until well browned and crusty, about 30 minutes longer.
Preheat the oven to 450 degrees F. Place a large 12-inch cast-iron skillet into the oven.
In a medium bowl, whisk together the cornmeal, flour, sugar, baking powder, salt and baking soda. Combine the buttermilk, 2 tablespoons of the melted butter and the eggs in a spouted measuring cup. Whisk the buttermilk mixture into the cornmeal mixture until just combined.
Carefully remove the cast-iron skillet from the oven and pour in the remaining 2 tablespoons melted butter. Pour the cornbread batter into the skillet and spread evenly. Bake until the top is browned and a toothpick inserted into the center comes out clean, 20 minutes. Let the cornbread cool in pan for 10 minutes before turning out onto a cooling rack.
Cook's Note: To enjoy this cornbread on its own, bake it in a 10-inch cast-iron skillet for a fluffier texture.