Saw this guy pop as 59-61, I leveled there through these levels camping the longsword and saw him even con at each of these so I'm sure.
Longsword is the rare drop (or I was just unlucky), most common is the cloak.
He pops in the room to the south of Stonemaw, and "circular dead end room at the north end" mentioned below is a pretty good description. It is immediately north of the most northern entrance to the Delve, +602 -1173.
The other mob that drops this sword is at the intersection in the coridoor that connects this room and Stonemaw's room (you don't have to go near the latter), with a level 59-60 diviner as its PH.
Edited, Apr 4th 2011 8:08am by deeprave