I smell a Nigerian rat in this one. Naranja, if he has the real thing, could just as well go directly to Joseph Fara, get the alleged document authenticated, and then sell it or get a very substantial reward for it. Instead, he's chosen to go anonymously to eBay. Also the things he's allegedly written are in the broken English that's characteristic of Nigerian scam letters.
You're right, and the shocking gullibility demonstrated by most on this thread is proof that P.T. Barnum was a wise man indeed.
I happen to own a nice bridge I've been thinking about selling; perhaps some of these folks might be interested in checking out my eBay auction...