Biggles And The Lost Sovereigns

First published in seven parts in Look and Learn, issues 82-88, August 10, 1963 to September 21, 1963.
Back in 1942 as Singapore was preparing for the Japanese invasion, 20,000 gold sovereigns were put on a schooner named Vagabond. Soon after, the ship disappeared. Twenty years later, a native was found in a canoe with a necklace made of some of those sovereigns. Biggles is asked to go to the Mergui Archipelago to investigate.