In a lg bowl combine chicken quarters, garlic, oregano, pepper and coarse salt to taste, vinegar, oil, prumes, olives, capers and juice, and bay leaves. Cover and let marinater, refrigerated, overnight. Preheat overn to 350 F. Arrange chicken in a single layer in one or two large, shallow baking pans and spoon marinade over it evenly. Sprinkle chicken pieces with brown sugar and pour white wine around them. Bake for 50 min to 1 hr, basting frequently with pan juices. Chicken is donw when thigh pieces, pricked with a fork at their thickest, yield clear yellow (rather than pink) juice. With a slotted spoon transfer chicken, prunes, olives and capers to a serving platter. Moisten with a ffew spoonfuls of pan juices and sprinkle generously with parsley or cilantro. Pass remaining pan juices in a sauce boat.