Credor GBBD987 Skeletonised Platinum 6899Model: Credor GBBD987 Skeletonised Platinum 6899 Year: July 2000 Features: The Origin. In 1996, two of Seikos most decorated employees created a watch that shaped the future of Japanese haute horlogerie. That watch in question was the Credor GBBD987 a skeletonised dress piece in solid platinum, housing the razor thin 6899 calibre. Mamoru Sakurada designed, built, and assembled the movement, while Kiyoshi Terui engraved every available millimetre by