Naw, you guys are all wet, that pistol was clearly from the Tirpitz. The officer who held it was on-shore for liberty when the RAF bombing leading to the sinking of the Tirpitz occurred. The salt was introduced upon taking the motor launch from ship to shore but the corrosion was minimized by the cold temperatures of Norway slowing down the kinetics of iron oxidation...
Seriously, that is a very cool pistol. I'd be very happy to have such an example