Bring a large pot of salted water to a boil. Add potatoes; cook until
tender but still firm, about 15 minutes. Drain and transfer to a large
bowl.Place eggs in a saucepan, and cover completely with cold water.
Bring water to a boil. Cover, remove from heat and let eggs stand in hot
water for 10 minutes. Remove from hot water and cool. Peel, chop and
add to potatoes.
In a small bowl combine lemon juice, oil, sugar, seasoned salt,
Worcestershire sauce, mustard powder and black pepper; mix well. Blend in
mayonnaise. Pour lemon dressing over potatoes; stir to coat.
Mix in green onions, celery and parsley. Refrigerate for at least 2
hours before serving.