In 4-quart saucepan or Dutch oven, place potatoes; add enough water to cover. Heat to boiling. Cook about 20 minutes or until tender. Drain; cool slightly. Cut into 1-inch cubes. Place in large nonmetal bowl. Sprinkle with vinegar and salt; toss to coat. Let stand 30 minutes.
Meanwhile, in 2-quart saucepan, place eggs in single layer. Add enough water to cover eggs by 1 inch. Heat to boiling. Immediately remove from heat; cover and let stand 15 minutes. Drain; rinse with cold water. Place eggs in bowl of ice water; let stand 10 minutes. Drain.
Peel and chop eggs. Add to potatoes with remaining salad ingredients; mix gently.
In small bowl, mix dressing ingredients. Pour over salad; mix gently to coat. If desired, garnish with additional sliced green onions.