Re-engraving a mystery. 1938 proof nickels challenge experts

Re-engraved hair ribbon at back of Jefferson's neck.
Normal hair ribbon on back of Jefferson's neck
Five varieties of proof 1938 nickels with re-engraving have been identified so far.

Re-engraving a mystery

The unexplained re-engraving at the Philadelphia Mint of an obverse and reverse pair of 1938 proof Jefferson nickel dies is not unique after all. At least five different 1938 proof nickel obverse dies were enhanced by an engraver who hand carved details directly into working proof dies, and it remains to be seen if any 1938 proof nickel dies have the elusive “normal” design.

Resource: “Numismatic News” Sept. 30, 2008.