A possible lead on a Hebrew Audio version can be found in this Empire video clip:
In the information of the video they note “Hebrew - Azgad Yossi”.
The audio sounds like a clean recording, not a traditional international audio where they dub over the movie. Don’t know at this point if there is any more to it.
In a few years if your nephew is still into it, can go down this worm hole of Vader’s chest plate fonts:
Ok, the youtube video, the Hebrew part, is nonsense! hahah, if i translate from the hebrew to english he sais “How am i, how are you” hahha.
The other page, i didn’t undestraned 😦
But in a few more years he will know Hebrew well enough to see the movies in English and subtitles, hehe.
But thanks for the help!