I guess that will be an easy one. :)

I sold this for 75 keys pure, in one week. It was the only one for sale, only two are in existence.

Outpost trade: http://www.tf2outpost.com/trade/26654110#latest

Screens of the trade: http://imgur.com/eQsviYr

http://imgur.com/Q2J6hly

Snapshot of my backpack: the 75 keys obtained are grouped in "New Items", after the sniper rifle fabricator, all coming from Ordovician: http://backpack.tf/profiles/76561198096389539

Snapshot of Ordovician's backpack: http://backpack.tf/profiles/76561198012351180 (the hat is in "New Items", too)

I hope everything is done right!