Germany, Kriegsmarine. A Wartime Signed Portrait of U-Boat Ace Karl-Friedrich Merten

(Kriegsmarine Porträt mit Unterschrift). A rare wartime signed portrait of U-Boat ace Karl-Friedrich Merten, depicted in uniform and with an extensive array of decorations clearly visible, the image overlaid by Merten’s handwritten signature in black ink, the reverse with studio marks and an illegible date stamp, measuring 102 mm (w) x 148 mm (h), in extremely fine condition.