I went back in just now and tried switching the forge pieces around to the heroes in the area and it did not solve the problem. However, it has been a week since I did the quest. Perhaps it is one of the heroes I didn't try (I have about a dozen).
Even if that would fix it, it is still a problem as there is no way to track which hero started the quest and no logical reason why only they could finish it. This should be fixed (and what would happen if I lost that hero but had all the forge pieces?)
