Curator's Addendum
The Curator's Addendum is a correction to Renathal's Notes on the sinstone of Wrath in Sinfall written by the Curator.[55.3, 39.6] The note disappears after completing 
[60] The Meaning of Wrath.
Renathal.
You are confusing the Stonewright with the original Harvester of Wrath. She still exists, but had her power stripped and given to the Stonewright long ago.
If memory serves, the Stonewright was the first venthyr forged of a mortal soul to assume the role of a venthyr. She did... horrible things... in life in the name of protecting her people.
I have not seen the original Harvester of Wrath for a few epochs.
However, as to the location of the Stonewright's sinstone, she secured it after the incident with the Accuser and the Lord Chamberlain. We would have an easier time retrieving something from the Jailer than recovering her sinstone now.
Ask me these things. I am the specialist after all.
Patch changes
Patch 9.1.0 (2021-06-29): Added.