stuck in Bst epic 1.0Follow

The other day I went after the Draz Nurakk Images without proper preparation. My friend and I got killed, picked up some help and went back to do the killing.
The problem is, I only got 5 shards of broken glass. I assume one of the images got killed at some point, but poofed before I was able to loot it.
Is it possible to get Dumul's seal again to redo this portion of the quest?
If I say to Dumul that I need another seal, I get the "duplicate lore item" message. Apparently, he will only give another Official Seal of Khati Sha.