I've got a ranger who did the Xyfl scale quest. Any decently-levelled ranger, monk, rogue, or halfling can do the quest. One of the Shackle quests out of Cabilis East details this pretty thoroughly, but I'll summarize what I did.
I dropped down to OT with carnelians in tow. Camo'ed up and ran to the narrow tunnel where you can approach Tektite from the rear. If you're not a caster with this spell, bring a friend or buy a potion. Turned on Sneak, and crept up. I clicked to trade until I found the further point away that I could make the trade, and handed him the two gems, unstacked. BING!
Of course, the downside was that some NPC nearby noticed me, aggroed both gargoyles, and I got killed. Camo, /corpse /corpse /corpse, loot at book, and leave.
I've been trying to buy the remaining scales in the Bazaar. I've got Azdalin's, but not Gylton's. How do I know which one I have? If you have a Magelo account, just synchronize and look at the item properties. Magelo's database will tell you the 'true name' of any item.
Don't have Magelo? Get it.
Edited, Wed Mar 19 17:44:07 2003