Link Knockmany Passage Grave Hob Apr 18, 2008 Armagh Observatory Page mostly describes directions for a walk from 2004, but also includes a nice old photo before the modern mound was added.
Ah! Am so glad to have found this here. I had the real thrill of meeting Mark Bailey a week of so ago - as arranged by some friends of friends. He and his wife accompanied a small group of people up to Knockmany - where we got to go inside.