Preheat oven to 350 degrees F (175 degrees C). Grease a 2 quart casserole dish.
Bring a large pot of lightly salted water to a boil. Add macaroni and cook for 8 to 10 minutes or until al dente; drain.
Heat the milk in a small saucepan. Stir in mustard, Worcestershire sauce, salt, and hot sauce. Set aside.
Stir 1 1/2 tablespoons butter and 3 cups cheese into the drained macaroni. Pour the hot milk mixture over the cheese and macaroni. Transfer to prepared baking dish. Sprinkle remaining 1/2 cup cheddar on top. Combine the bread crumbs with the melted butter, and spread over the top. Sprinkle with paprika.
Bake in preheated oven for 30 minutes, and then place under the broiler for 1 to 2 minutes.