Revealing mistake: During the fight scene in the belly dancer's room, Bond spins the bald guy around to avoid being hit by a chair. When the bald guy gets hit in the back with the chair, you can see a large rectangle of padding under his jacket.
Revealing mistake: At the start of the film, when the gangster lands on Scaramanga's island and enters Scaramanga's fun house, he encounters a scene where some dummies of Al Capone and some other gangsters come out of an area, guns blazing... With the first burst of machine gun fire, the dummy "blinks"... (00:05:25)
Revealing mistake: In the shot where Bond rams the long-tail boat of the karate experts, you can see that the boat is split into two pieces, and the bow is already sinking before the collision. (00:59:30)
Revealing mistake: When Nick-Nack pulls the money from the dead gentleman whom Scaramanga kills in the game before the opening credits, you can see a "wax figure" of James Bond pointing his gun. However, he is moving and not standing completely still like a wax character or mannequin would. (00:07:55)
Revealing mistake: Scaramanga's jet-car fires up its roof-mounted jet engine and begins to roll forward in the hangar. Despite the fact that we hear the turbine whining loudly at increasing RPMs, the flimsy tan sheeting hanging in front of the jet intake is not sucked in, or even disturbed at all by the air flow. (01:29:05)
Revealing mistake: During the intro, the first Bond "dummy" and the second one when Scaramanga fires are different. They're either real and dummy or both dummies, but the first one has a concentrated look, and the second one has a worried look.
Revealing mistake: Scaramanga's woman is taking a shower. When Bond gives her a towel you can see she's not naked but wearing a skin-colored top. The top is also visible when looking at the reflection on the mirror to the right of them. (00:28:35)
Revealing mistake: At the end of the film where Nik Nak is throwing unopened bottles at Bond from the junk's bar area not one of them appear to have any liquid in them. Bond never got wet and neither did the sheets on the bed or the floor.
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]