It reminds me something Brick Price said in "Return to tomorrow":
"In fact, there were at least two different kind of props that we always made: a "hero prop" or "principal prop" for the close-ups, and the principal dummy prop to stand in for the hero weapons because they were too important to be injured.
To give you an example, for the wrist communicators, we made what we called the principal dummy prop. It was made for principal actors and it looked like the other wrist communicator prop but it was gross in its details, because you wanted to see the details when it was moving around.
Now, when they did the close-ups, they went to the principal props.
It was really stretching the imagination a bit, because the design changed, after a fashion, but the principal props were supposed to look like the principal dummy props, and in fact, they did. But someday, some smart blooper-catcher is going to find out the difference between the two."
Well, here we are.