Put in a ticket and a bug report. GM responded with the normal, We can't help you, ask the players response. Nothing on the bug report yet.
I did get lucky and someone else was on the quest to kill the Cuthraul, but I got nothing after tagging it. I did kill Drugrir and got his quest item before this problem came up.
Selling it might be possible. Maybe they can replace it. Always thought quest items could not me sold. I have a couple others in my inv.