In a covered saucepan, cook potatoes (still whole and unpeeled) in boiling salted water for 25 to 30 minutes until fork tender; drain well and cool long enough to handle. Peel (with a paring knife) and cube potatoes. Transfer to a large bowl; add onions and eggs. Combine mayonnaise or salad dressing, sugar, celery seed, vinegar, yellow mustard, salt and curry powder. Add mayonnaise mixture to potatoes. Toss lightly to coat potato mixture. Cover and chill thoroughly (preferably overnight). Makes 8 servings.
Serve with additional hard-cooked eggs, sliced, as decoration and sprinkle lightly with paprika (and parsley, if desired).
You can double the recipe (use 5 lbs potatoes) for larger groups.