Preheat oven to 350°F.
Remove giblets and necks from the ducklings. Rinse everything with running cold water and drain. Pat ducklings dry and cut each into quarteers; trimming excess skin and fat.
Place a rack in roasting pan. Place duckling quarters, skin side up on rack and sprinkle with salt and pepper. Roast in oven for about 2 hours or until ducklings are golden and tender.
While bird is roasting, place giblets and neck into a pot with enough water to cover. Add 1/4 teaspoon salt, bring to a boil then reduce heat to low and simmer for 1 hour. Drain, reserving 1 cup of broth.
In saucepan, combine the port-wine, orange juice, lemon juice, mustard, ginger, 1/2 teaspoon salt, 1/2 cup currant jelly and the reserved broth. Bring to a boil and then reduce heat to low, cover and simmer for 10 minutes. In a small bowl or cup mix 2 tablespoons flour and 1/4 cup water. Gradually stir into simmering liquid in saucepan. Cook until sauce thickens slightly and is smooth.
In a cup, stir 1/4 cup red-currant jelly and 1 teaspoon of water until smooth. About 10 minutes before duckling is done, brush duckling quarters with jelly mixture.
To serve, arrange the duckling on a warm platter with oranges and olives as garnish. Serve the sauce in a gravy train or small bowl.