In small bowl, soften gelatin in cold water. In 2-quart heavy saucepan, stir together egg yolks, sugar, 1 tablespoon of the orange peel, orange juice, lemon juice and 1/8 teaspoon of the salt. Cook over low heat, 8 to 10 minutes, stirring constantly, or until slightly thickened; remove from heat. Add 2 tablespoons of the butter, gelatin and 1 teaspoon of the vanilla; stir until butter is melted. Fill large bowl with ice water; place saucepan in water. Cool egg mixture, stirring occasionally, about 10 minutes or until thickened.
In medium bowl, beat whipping cream with electric mixer on high speed until stiff peaks form. Reserve 1/2 cup of the whipped cream; refrigerate. Carefully fold orange mixture into remaining whipped cream. Refrigerate while preparing tart shells.
Heat oven to 425°F. Cover outsides of 6 (6-oz) custard cups or ramekins with foil; spray with Crisco® Original No-Stick Cooking Spray. Place cups upside down on 15x10-inch pan with sides. Unroll pie crusts; roll each into 12-inch round. Using 4 1/2-inch scalloped or round cookie cutter, cut 3 rounds from each crust. Place dough round over back of each custard cup, pressing dough to fit around cup. Prick dough several times with fork.
Bake shells 10 to 13 minutes or until golden brown. Cool 15 minutes. Carefully remove shells from cups; place open side up, on cooling rack.
In small microwavable bowl, microwave chocolate chips and remaining 1 tablespoon butter on High 10 to 20 seconds, stirring every 10 seconds, until smooth. Stir in remaining 1/8 teaspoon salt and 1/2 teaspoon vanilla. Brush thick coating of chocolate mixture over bottom and up side of inside of each shell. Let stand 5 minutes or until set.
Evenly divide orange filling among shells. Top tarts with reserved whipped cream and remaining 1 tablespoon orange peel. Refrigerate 1 hour (filling will be soft). Store covered in refrigerator.