The Buff Bone Dithers

Back to dithering over the buffalo skull piece.  I sucked out the section of spongy bone and redid it lighter.  Haven't figured out how to get the stipple look yet.  Used the syringe tip and just swizzled it around to get what I have here.  I enjoy this piece and will probably continue to dither at it until it is what I want it to be.  I still don't think the prominence of the spongy section is good......maybe got it too dark again???  Anyones thought/ideas would be welcomed.