My guild killed Nortlav the Scalekeeper in "The Hole" and looted a red scale for one of our bards. She already had the white scale I think. Anyhow, what I heard from my fellow Nortlav killers was that he was RUMORED to drop the white scale VERY RARELY. The point I am trying to make is that you should not consider Nortlav as a source of white scales.
By the way, Nortlav is a total ******* to defeat in combat. But, he is definitely killable with the right groups and levels.