From what I can see, I don't think you should have that quest.
After recruiting Elly and going to the ruin in the south of Begus, you find a broken switch, which gives you a quest to go to the mechanic. Only when you talk to the mechanic before finding the old documents in the Tower of Ash does he give you the quest to search for them.
Since the quest is skipped when you do it with the documents already in your inventory when you talk with the mechanic, I set the quest to finished, since it otherwise would remain in your questlog forever.
It seems like there are cheated items in your inventory, so that could be a possible cause for the mess. Some events are automatically advanced to the next step when the quest item is in your inventory when you talk to the npc. If you cheat, make sure not to do it with quest items, or you could get issues like this again.