I think that if the truncheon were newly discovered by the English-speaking world, "jitte" would be the best choice for its English name. However, "jutte" is already out there, and common. We could bypass the question and just write "十手".
(Not that using Chinese characters frees us from ambiguity. One interesting and annoying ambiguity is that the same character is used for catapult and cannon. Makes it hard to tell which is used in early sources. Even descriptions of explosions doesn't help, since catapults were used to throw gunpowder bombs.)
Of course, if I was the One Who Decides Correct Usage, I could pick one and decree it to be the One True Name for the truncheon. But since I'm not in that position of authority, I'll just have to let the community decide.
My jutte/jitte, except for some overtly modern martial arts ones, are shown here:
http://www.vikingsword.com/vb/showthread.php?t=16220