Combine the gelatin, ¾ cup of sugar and salt in a saucepan. Beat the egg yolks and milk together and stir into the gelatin mixture. Place over low heat and stir constantly until the gelatin dissolves and the mixture thickens slightly, 3-5 minutes. Remove from the heat and stir in the lemon rind and juice and the vanilla. Chill, stirring occasionally, until the mixture mounds slightly when dropped from a spoon. Beat the cottage cheese until smooth and stir into the gelatin mixture. Beat the egg whites until stiff; gradually add the remaining ¼ cup of sugar and beat until very stiff. Fold into the gelatin mixture. Fold in the whipped cream. Turn into the prepared pan and sprinkle with the remaining crumbs. Chill until firm, 2-3 hours.