For those interested, we have figured out exactly how to read the RUNES that lead to the skelly chamber and the nice subterrane chest dropping lots of named goodies, to include icy raiments...
There are three entrances, as far as I can tell and accord with the "G" runes on the skelly carving's eyes in these pictures. The skelly carving is found after the first portal on the way to the hound where you have to kill the two spiders.
If the "G" rune is over the skellies' left eye (right if you are lookin' at him - note picture below), then it is the lower room (note left = lower). We will call this Entrance 1. Directions to this entrance are below this picture.
ENTRANCE 1) Head like you are heading to the hound. In the big room (this room is prior to going through the door to the east entrance portal where beholder and mind flayer are), drop down hard two levels to your left and go underneath where you entered the room to the NE corner of the room. There is a mindflayer there.
If the "G" rune is over the skellies' right eye (left if you are lookin' at him - note picture below), then it is the upper room (further north). Directions to this entrance are below this picture. We will call this Entrance 2.
ENTRANCE 2) The same directions to the big room as above. Except, instead of dropping down two levels, drop one and stay head N in the center. There is a door there. Go through that door, make a left, go up ramp, make a quick right, drop down and then another quick right and you are there. There will be a small fight and a shrine.
If neither eye has a "G" symbol, then you are facing entrance three, which is easier to recall, regroup and rerun than it is to head all the way to through the east subterrane.
ENTRANCE 3) On the east side, almost to the hermit beholder room.
I hope this helps some of you score some shiney lootz. Have seen 3 icy raiments drop in same chest, so get it while it is hot!
Good luck and good lootz!
~ Dex (Argo)