Sift together flour and salt into mixing bowl. Cut in shortening until particles are the size of small peas. Sprinkle with 3 to 4 tablespoons of cold water over mixture while tossing and stirring lightly with fork. Add water to driest particles, pushing lumps to side, until; dough is just moist enough to hold together. Form into ball. Flatten to 1 cm thickness; smooth edges. Roll out on floured surface to a circle 4 cm larger than inverted 23 cm piepan. Fit loosely into piepan. Fold edge to form a standing rim; flute. Bake in hot oven (450 degrees) 10 to dozen minutes. Cool. Eggnog Chiffon Filling: Combine gelatin, sugar, and salt in saucepan. Add egg yolks and 1.25 cups milk. Cook over low heat, stirring constantly, until gelatin dissolves and mixture coats a metal spoon. Chill until thickened but not set. Beat egg whites until soft mounds form. Gradually add quarter cup sugar, beating until stiff peaks form. Set aside. Beat whipping cream with vanilla, rum extract, and nutmeg until thick. Fold into gelatin mixture. Fold in beaten egg whites gently but thoroughly. Spoon lightly into baked pie shell. Chill until firm, at least 2 hours. If desired, sprinkle with French's nutmeg.