1. Combine eggs and egg whites in medium bowl; beat until foamy. Set aside. Put margarine in double boiler. Melt margarine over simmering water. Add lime peel and lime juice; mix well.
2. Add egg mixture to margarine mixture; cook and stir until thickened, about 6 minutes. Remove from heat; cool completely.
3. Cut lady fingers in half lengthwise. Line bottom of 1-1/2-quart souffle dish or casserole dish with lady fingers. Cover with 1 cup of lime mixture. Continue layering until all lady fingers are used. End with layer of lime sauce.
4. Cover tightly; refrigerate 6 hours or overnight. Garnish with grated lime peel, if desired.