dirk is dropped off of the dragoon elite that runs the path from nek citidal to the bridge. he will drop that or gul'thex bracer i belive it is. he is like anywhere from lvl 25^ - 27^(maybe 28^) with 3 followers. however he is killed fairly often tho as he is needed for multiple quests and of those is a book quest that requires 30!!! elite kills, pretty bad considering he only pop's bout once every 15 mins. you might also chk for a ornamental dagger i think it is. its a player crafted dagger fairly nice too, has a nice range of stats on it. and if u can get a steel one from gettin a rare even better
*lil extra tidbit i have had a severed cuiribiolli apron drop off aswell as his regular loot. supposedly this can be used to craft rare cuirblah stuff, doesnt work yet, but most likely will in the future