Thoroughly mix gelatin, 1/2 cup sugar, and salt in saucepan. Beat together egg yolks, fruit juices, and water; stir into gelatin mixture. Cook and stir over medium heat just till mixture comes to boiling. Remove from heat; stir in peels. Chill, stirring occasionally, till mixture mounds slightly when dropped from a spoon. Beat egg whites till soft peaks form. Gradually add 1/3 cup sugar, beating to stiff peaks; fold in gelatin mixture. Pile into cooled baked pastry shell. Chill till firm. Trim with whipped cream and thin orange slices cut in fourths.