Chop giblets. Brown garlic in 6 tablespoons butter in skillet; remove garlic. Saute onion and giblets for about 10 minutes in garlic butter; add mushrooms, 1/2 c. Maderia, walnuts and seasonings. Cook until mushrooms are tender and liquid is reduced. Spoon stuffing into grouse; truss. Dot each grouse with 1 teaspoon butter. Place grouse in small brown paper bags; fold over ends. Brush paper bags with shortening on all sides. Place in shallow roasting pan. Bake in 400-degree oven for 10 minutes; reduce oven temperature to 350 degrees. Bake for 1 hour and 15 minutes longer. Bring bouillon and remaining wine to a boil in saucepan; add Brussels sprouts, cooking just until tender. Drain; toss in remaining butter. Serve with grouse.