Locating a surviving Diadem gun turret

A remembered twin naval mounting is initially placed in India before the location is corrected to Pakistan's naval headquarters in Karachi. The turret is associated with PNS Babur, formerly HMS Diadem. The underlying question is whether any twin 5.25-inch mounts survive. A single mounting in Gibraltar provides a comparison. The Karachi example is described as the only possible twin the participants had found, leaving the existence of other survivors open.