In 1972, FA Porsche established Porsche Design with a vision for clean, highly functional products, a philosophy that aligned naturally with IWC and led to a collaboration from '78–'97. Their '78 Compass Watch, ref. 3510 embodied this shared ethos, introducing a bold, utilitarian design featuring an uncommon black PVD finish and a lightweight hardened aluminum case, with an olive green variant also produced. Its most distinctive innovation was a hinged case that opens via pushers on the lugs to reveal a liquid-damped compass and emergency mirror, while the movement was engineered with non-magnetic components to prevent interference, and the compass itself featured tritium lume for low-light usability—making it one of the most inventive mechanical tool watches of its era. On offer is an updated ref. 3551 (introduced later in '85) which notably features a moonphase complication at noon. It is also double signed by Adron, which we were not able to find information on, but perhaps this mystery can be solved in the future. This example has remained in excellent vintage condition with a mint dial/hands and case/bracelet showing minimal distracting wear in its PVD. For anyone who loves horology and adventure, this timepiece really embodies the types of interesting treasures CCNY seeks to find. Dial: No notable blemishes under magnification. All the tritium lume plots are present and full and have aged well. Hands: Are matching and their lume is stable. Case: Light signs of use with minimal wear in the PVD coating. Correct unsigned crown. Bracelet: Correct IWC signed, fitting an approximate 7 inch wrist. Crystal: Clear. Accessories: NA The movement is running well on our timegrapher and comes with our 6-month mechanical warranty.