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: