*In a large bowl, combine potatoes, hard-boiled eggs, celery, chopped onion, salt and pepper; set aside. For Dressing: *Combine beaten eggs, vinegar, sugar, dry mustard and salt in a saucepan. *Cook and stir over medium heat until thickened. Cool. *Stir in mayonnaise; mix well *Pour over potato mixture; toss to coat. *Refrigerate for several hours.