Ok I dont know the exact loc, but as you are heading from the entrance you will come to a HUGE area with several veins that break off, one to kings, one to exit, etc. If you were to head to the King's room (right) this guy spawns in the alcove that is just to the left of that.
Ok just looked at map on EQAtlas, I would say it is near pos 100 pos 500, in that little dead end there. Killed him twice tonight with 4 ppl (65 chanter, 65 druid, 65 warrior, 59 monk). Much easier than King or Overseer.