Take the Proof of Deed back to Mountaineer Pebblebitty.
I can't believe Pebblebitty doubted the authenticity of the horn. Between you and me, I think she's just jealous. I know she really wanted to kill that beast herself, what with the 'incident' and all.
So you need a proof of deed? After the contribution you just made to the museum, it won't be a problem.
<Curator Thorius begins to fill out a large document.>
There we go! You can take that back to Pebblebitty.