Place potatoes in large pot, cover with water, add a tablespoon or so of salt, cover and bring to a boil.Reduce heat and simmer for 15 to 20 minutes. When you can easily pierce with a fork, they are done.In a medium bowl, combine sour cream, mayonnaise and mustard.Stir in onions, celery, pickles, eggs and fresh dill. Add salt and pepper, to taste.While potatoes are cooking, make an ice bath for the potatoes. Add cold water to a large bowl and add ice. Drain potatoes and add to ice bath.Once cooled, peel potatoes by gently pinching the skin and pulling it away.Chop potatoes into bite-sized chunks and place in a large bowl.Scatter the vinegar over the potatoes and lightly season with salt.Gently fold in the mayonnaise mix, trying not to mash the potatoes.Garnish with sliced egg, dill and/or fresh ground pepper (optional).Refrigerate until serving.