I buried the scroll after getting it back from the thieves as requested by Wael's (?) voice, and then went on to report to Grimda. The result is that she does not trust me, and, I suppose, I will never get access to the Elder Archives.
Here is what she says:
Afterwards, I can no longer get a dialogue with her; only a pop up bubble appears above her head. I wonder what this conclusion of the quest depends on?
I did quite a bit of quests in between, including the Tower in Heritage Hill (where I chose to enhance my character with the souls). A quick search on Google after I finished the quest revealed that technically she should have approved my decision?
I suppose the only way to access the Elder Archives now is through breaking in?