this quest has buged out on me. Since I entered the Keyhole column on the west of the map first and used the keystone key I found in the crypt in Gilead I had no keystone to use on the keyhole column near Fursanden, i had to use the console command player.additem 025b33 1 to get a keystone to enter it. I didn't pick up the 3 keystones in that dungeon that were on the table with the note because I couldn't see them because they wer almost invisible. Now that I have picked up all three statues and used the console command on the remaining 2 keyhole columns to gain access to get the statues and I'm back where I have to place the statues in the circles the statues do nothing when droped in the circles....quest is completely bugged and broken for me now.
Here is the current saved game, hope yu can fix this one.