Just for reference, I have a coticule that doesn't have the slate attached anymore so that gives me a really narrow hone by flipping it making the width the height and it works wonders on warped, smiling or (insert blade status here) it just does wonders. So instead of cutting a stone if you haven't done it already maybe you should try removing the slate from the coticule. Some of the vintage ones come off really easy and that gives you a bbw and coticule narrow hones.