Once above you should see this!
You have to kill Wyverns in this area and the above until a talon drops, be warned thieves this will lower your hide lvl greatly.
This is the hex to the above area with more Wyvern ( climb up ) , they also see through hide much easier and have hit me for as much as 13k
Above you should find yourself here:
This NPC is literally a few steps east, hand in your talon when possible and you can now go up to level78!
Sometimes the Wyvern like to get stuck on clouds, throwing an item several times if you're hidden will make them eventually come to you. Tiers have the same effect.
These Wyverns appear to share one spawn for both floors, so kill em all!