Crack turkey carcass. Combine carcass and 3 quarts water in a large stock pot; bring to a boil. Reduce heat; cover and simmer 1 hour.
Remove carcass from stock; set stock aside. Remove any meat remaining on bones; discard bones. Chop meat into bite-size pieces, and combine with chopped turkey; cover and refrigerate.
Combine oil, bacon drippings, and flour in a large stockpot; stir until well blended. Cook over medium heat, stirring frequently, until roux is the color of a copper penny. Stir in celery, onion, green pepper, garlic, and parsley; cook over low heat 20 minutes, stirring frequently. Add okra and sausage; cook an additional 5 minutes, stirring frequently.
Add reserved turkey stock, remaining water, tomatoes, Worcestershire sauce, bacon, salt, hot sauce, red pepper, and bay leaves; simmer, uncovered, 2 1/2 hours, stirring occasionally. Stir in reserved turkey, and cook, uncovered, an additional 30 minutes. Remove and discard bay leaves. Stir in lemon juice and brown sugar.
Ladle gumbo over hot cooked rice in individual bowls and serve immediately.