Soften gelatin in water. Drain cherries, reserving juice. Beat egg yolks and add juice from cherries (¾ c.), salt and ½ c. sugar. Cook over low heat until thickened, stirring constantly. Stir in softened gelatin and stir until it is dissolved. Cool slightly and add lemon peel and drained cherries (1½ c.).
Beat egg whites until soft peaks form when beater is lifted. Gradually add remaining ¼ c. sugar, 2 tblsp. at a time, beating thoroughly after each addition. Beat until stiff peaks form. Fold into gelatin mixture. Pile lightly in pie shell and chill until firm.
When ready to use, garnish each serving with whipped cream.