Arrange nut meats in a single layer in a shallow pan; turning occasionally, toast in a slow oven (300°) for 5 to 7 minutes; remove from oven.
Increase heat to 350°, and toast bread cubes until golden brown.
Heat water, pour over bread cubes, and let stand 10 minutes.
Combine nut meats, bread cubes, orange peel, orange pulp, and celery.
Beat egg with the 1/2 teaspoon salt, pepper, and poultry seasoning; combine with bread cube mixture.
Pour melted butter into stuffing and toss well.
Rub inside of duck with the 1 teaspoon salt.
Spoon stuffing into duck; sew openings.
Place the bird, breast side up, in a roasting pan.
Bake, uncovered, in a moderately slow oven (325°) for 2 to 2 1/2 hours or until tender.
For a crisper skin, increase heat to a hot oven (400°) the last 30 minutes of baking.