Word is Hatori is closing down. So if you want a header...........
I found this header on a muffler combo, fits the OS, has more drop to it, looks to be at least 30mm, could be 35, haven't measured it. Not using the can. Actually like this header more, not sure how long it will last though.
http://www.agmhobby.com/item/agm30-c...ust-p-253.html
I can't find the Hatori headers anywhere either. If this header fits, it should work. With a small mod to the exhaust tube, service life should not be a problem.