Place potatoes in a large pot and cover with cold water. Add a couple teaspoons salt and set burner to high. Once boiling, cook the potatoes for 20 minutes or until tender. Drain and chill.
Peel and cut potatoes into ½ inch cubes and place in a large bowl.
Chop up celery, green onions and hard-boiled eggs and add to the potatoes.
In a medium size bowl whisk together mayonnaise, milk, mustard, brown sugar, white sugar and vanilla. Pour over potatoes and mix well.
Add salt and pepper to taste.
Garnish with green onion greens, cover and chill for at least 2 hours.