Audio problem: The voice of Lt. Hip, Bond's assistant in Asia (played by Soon-Tek Oh) changes during the film, usually depending on whether it's an inside or outside scene. In all the outside scenes, his voice is much higher and shriller, so it was probably dubbed by a different actor.
Audio problem: In the teaser we see the hitman load his gun when he gets ready to kill Scaramanga. When Scaramanga walks into the room, the hitman aims for him. The gun makes a loading sound. Upon the hitman's arrival to the room he racks a bullet into the chamber therefore no other action would be required to make the gun ready to fire. A loaded gun does not make a sound when you aim it - and why would he have unloaded the gun while waiting for his victim? When you load the gun, the hammer is back and the gun is ready to fire. No further actions are necessary. And a professional hitman does not wait to turn off the safety on his gun until his victim has arrived.
Answer: I haven't been able to find any information on its whereabouts so my guess would be that ended up like most movie props do. Either as a souvenir for one of the people attached to the movie, (actor, director, etc.) in storage (in case it could be recycled as a prop in another movie) or simply discarded when it wasn't needed anymore.
Andreas[DK]