Boil shrimp in water until color changes. Set aside. Into large kettle put 4 tablespoons butter. Add okra and onions and stir frequently until okra is tender. Sprinkle with flour. Stir until smooth. Add tomatoes and paste and cook 10 minutes. To oyster liquor add water to make 8 cups. Pour into kettle. Add seasoning (except Worcestershire) and simmer 1 hour. Then add oysters and shrimp and cook 10 more minutes (or until edges of oysters curl) over low heat. Add crabmeat and Worcestershire and cook 2-3 minutes more. Serve over hot fluffy rice.