As of the picture in the bottom in the press, I see a lot of violation on the back. Hackberry is one of my favorites and it does really well if not violated, but if it is it'll really raise splinters and peel open. You could either chase down one more ring or you could back it as is. It wouldn't need a heavy backing; something like rawhide would work fine, but it would need a backing if you don't clean the back up. Just my two cents. That's a good, workable stave though.
With hackberry that has pretty thin rings, you can use a pretty course sandpaper to take it down a ring rather than using an edged tool and it'll be a little less likely to cut down a layer.