You can loot dragon scales from Phillipa 's house in Loc Muinne, but only after you progress past a certain point in act 3 and her house becomes accessible. Path is of no importance. You can get it regardless. Plus, i think only in iorveth path, you can find 1 dragon scale in a chest somewhere down the sewers, but beyond than that, i do not remember details. Dragon Scale makes the Hard Difficulty Set Pants, or the sword Zerrikaternment.