An elegant vintage Art Nouveau cast bronze letter opener modeled after an Unger Brothers mermaid design featuring curved blade and a handle decorated with an embossed image of a long-haired mermaid brandishing a trident among waves and water plants. Circa the late 20th century. Unger Bros. or Unger Brothers was a jewelry company in Newark, New Jersey, best known for their sterling silver Art Nouveau designs. The company was established by five sons from a German immigrant family. Antique and Vintage Desktop Accessories and Art Nouveau Decorative Collectibles.