In a large covered saucepan, cook hash brown potatoes in boiling water for 6 to 8 minutes or until tender; drain well. In a large bowl, combine potatoes and celery. Set aside.
In a small bowl, combine sour cream dip, mayonnaise, sugar, vinegar, mustard, and salt. Add mayonnaise mixture to potato mixture; toss lightly to coat. Gently fold in hard-cooked eggs. Cover and refrigerate 4 to 24 hours.
Before serving, garnish with lettuce leaves, celery leaves, and/or pimiento strips, if desired. Makes 20 servings.