Place potatoes in a stockpot and cover with water. Bring to a boil. Reduce heat; cover and cook until tender, about 20 minutes. Drain. When cool enough to handle, peel and slice potatoes; cool completely.
For the dressing, in the top of a double boiler or metal bowl over barely simmering water, heat 1 cup water, butter and vinegar until butter is melted. In a small bowl, beat eggs; add sugar and cornstarch. Add to butter mixture; cook and stir until thickened, 5-7 minutes. Transfer to a large bowl; cool completely.
In a small bowl, beat cream until stiff peaks form. Stir Miracle Whip into cooled dressing mixture; fold in whipped cream. Stir in onion, green onions, salt and pepper. Add potatoes; toss lightly to combine. Refrigerate, covered, until chilled.
To serve, top with hard-boiled eggs; sprinkle with paprika.