1. Place the eggs in a saucepan large enough to hold them in a single layer; add enough cold water to cover. Bring to a boil over medium-high heat; reduce heat and cook at a bare simmer 12 minutes. Rinse the eggs under cold water. When cool enough to handle, remove the shells.
2. To make the filling, hale the eggs lengthwise. Place the yolks of 4 eggs in a medium bowl and discard the remaining yolks. Chop the whites of two eggs and add to the bowl; mash well with a fork. Add the celery, carrot, scallion, sour cream, mayonnaise, vinegar, salt, and pepper; blend with a fork.
3. Spoon the filling into the hollows of the remaining 12 egg-white halves, mounding to fill. Place on a platter, cover with plastic wrap, and refrigerate until cold, at least one hour.