Nostalrius Begins - Quality wow vanilla realm (1.12)

Hello, I was on the quest "Mission: Possible but not Probable" when it bugged out and wouldn't give me the quest objective for pickpocketing the key from Silixiz, instead remaining at 0/1 rather than 1/1. I tried deleting the key and re-stealing it, but any time I pickpocketed the key from him it wasn't in his inventory.

Tried abandoning the quest and picking it up again, which deleted the items I got from killing the elite mob, but he still doesn't have the key for me to steal.

Would it be possible to have "Gallywix's Head", "Silixiz's Tower Key", and "Cache of Zanzil's Altered Mixture" given to me so I can complete the quest?