Thaw hens if frozen. Place a rack in a slow cooker. In a medium bowl, combine stuffing mix with seasoning packet, water, and 1/4 cup of margarine/butter. Stuff hens and place on rack in slow cooker. In a small saucepan, combine jelly, cherries, remaining butter/margarine, lemon juice, salt and allspice. Cook over low heat, stirring until jelly is melted. Reserve 2/3 cup sauce. Brush remaining sauce on hens in cooker. Cover and cook on low 6-7 hours. Serve whole or cut hens in half with kitchen shears. Spoon reserved sauce over hens at serving time.