Japanese WWII Ships Brass Deck Screw, Wreck Recovered

Original era manufacture. Large, solid brass deck screw with Japanese characters, measures 53 x 30 mm.Recovered in the 1960's by a husband and wifeworking at the US installation on Kwajelein, who took up scuba diving to pass the time. Comes with a handwritten 3x5 card used in an old museum display established by the couple.