Rub the ducks with oil or bacon grease. Place in oven. Bake for 2 1/2 hours until done. Let cool. Remove the bones. (May cook the ducks the day before.) Mix chicken broth, brown sugar, wine vinegar, soy sauce, cornstarch, water until smooth. Cook until bubbly and clear. In another pan, heat water chestnuts in oil for 2 minutes, then add to mix. Put the duck pieces in pan, pour mix over. Add mandarin orange. Cover and heat until hot. Add the almonds. Serve with steamed rice.