The Walther air pistol originally used in promotional photography for From Russia With Love sold recently at action for $300,000.
When it was realised that a prop PPK had not been sent along for the photo shoot with Sean Connery an air pistol belonging to the photographer was used instead, with the idea of airbrushing out the long barrel later.
However, that step was overlooked and so the long barrelled Walther can be seen in artwork for the second James Bond film and several others after.
Source: The Daily Caller