Fabled Sash of the Dragonborn  

 

Youve first got to get the south key off of the end "boss" monster in the west wing(who is an uncommon spawn in my experience so you may have to camp it for a while).

But, to backtrack a little first. You need the tallow marked candle(i believe its called) as a random drop off the golem mobs guarding the doors or any of the monsters in the lower area(just jump off the ledge). This will get you into the north wing door.

Once you get in the north wing you pick up the groundspawn key that opens the door to the north bosses room. The groundspawn is in the room that is surrounded by the pathways and isnt connected to the outer walls. Sorry if that isnt clear but its the best explaination I can give. Once you get this groundspawn key, enter the bosses room and kill him for the key to the west room. He isnt always up, so you might have to camp him for a few minutes as well. Respawn is roughly 7 or 10 minutes so it tends to be a short wait.

Once you are in the west wing go south through the collapsed wall area and open the door to the room at the end of the hallway. There is a groundspawn key in here that will allow you to open the door to the west wing "boss" mob, which as I mentioned before, gives you the key to the south.

I wrote this up at 2:30AM and am very tired, I do hope these instructions made sense. Good luck on the sash by the way.

Oh...and if you happen to know of a rogue who still plays the game(they are scarce lately imo), you can just have them open the doors for you rather than deal with the no rent keys.