1. Preheat oven to hot (400° F.).
2. Sprinkle the fish inside and out with salt.
3. In a skillet heat four tablespoons of the butter, add the onion and cook until it is transparent. Add the bread and cracker crumbs, the basil, parsley, one-quarter teaspoon salt and the pepper and mix. Stuff the fish with the mixture and close with skewers and string.
4. Place the fish in a greased, foil-lined pan, and bake until it flakes easily when tested with a fork, about fifty to sixty minutes. Brush frequently with the remaining butter, melted and mixed with the grapefruit juice. Three minutes before removing the fish from the oven, arrange the grapefruit sections on top and brush with the remaining mixture or additional butter