Help: cannot finish armorsmithing quest.Follow

I just finished all my quests with the NPC in Tanaris and obtained my glimmering mithril insignia, now when I try to go back to Grumnus Steelshaper he won't do anything and I still haven't become an armorsmith.

Is there a step I'm missing here or what's wrong? I don't have the final quest in my log to make him his items, so I'm a bit confused on what to do.

Please help!