"But excuse me, why would the letterhead of this thing be in English?"
That's a possible objection to legitimacy, but it wouldn't really surprise me to see a lot of stationary headings for global entities in English as well as the local language. I am assuming that the corresponding Arabic heading is on the right (can't read Arabic). I would guess that creating a fake Arabic document with a heading in English is a mistake the Israelis would not make.
here is an al Aqsa (THE al-Aqsa?) website. You'll need windows browser support of arabic. You can scroll on the hotlinks, though, and keep an eye on the bottom of your browser and the URL will show up in English, sometimes with key words in the address that tellwhat kind of info. lies under the button. We can check for some similiarities. I for one do not think this doc. is a 'fake' job. They would have too much to lose under intense international intelligence scrutiny:
http://www.al-aqsa.org/