1Bring a large pot of salted water to a boil. Add potatoes and cook until tender but still firm, about 15 minutes. Drain, place in a large mixing bowl and beat until smooth.
2Place eggs in a saucepan and cover with cold water. Bring water to a boil; cover, remove from heat, and let eggs stand in hot water for 10 to 12 minutes. Remove from hot water, cool, peel and chop.
3In a mixing bowl, combine the potatoes, eggs, onion, celery, relish and pimentos.
4Blend together the mustard and salad dressing, add to salad and mix well. Sprinkle with paprika and refrigerate until chilled.