page 338 Cold Days
Harry goes on to say that Rashid's job is so secret his eye gets it's own disguise when he isn't at the gates. This implies a whole lot of things, like just how old is Rashid? How long has he had the job of Gatekeeper? Who made the eye in the first place? And when did Rashid receive it? Since the eye is made of the same material as the gates, was it made at the same time?
I like your questions a lot. There's a post on the dresden files wikia about how Rashid's name is one of the 99 names of Allah. Which might be a clue to his real identity if you consider that Jim does not lightly choose names for his characters. They always mean something.
Rashid's eye and the Outer Gates are made of the same crystal. But then we get a clue from Jim in Cold Days that the Outer Gates that Harry saw was just a dumbed down version that his mind could cope with. I think that the 'crystal' is actually a force of Creation much like soulfire. It's made of sheer will - which translates to magic in reality. The eye isn't really just something physical, it's a purely magical object that can manifest a physical form and has a specific purpose (opens ways, sees all things) like Odin's all-seeing eye.
I still disagree with Rashid being Odin's missing eye. But maybe Rashid
has Odin's missing eye? If the beings of both the Greek and Norn pantheons guarded the Outer Gates before Winter took over, that means Odin must have had the eye then. He might've even been one of the first Gatekeepers.
And it's more likely that Rashid is Heimdall rather than Odin himself. As Jim is a huge Marvel fan, his description of Rashid fits in with the Heimdall in the comics. Rashid can Listen (like Harry) and he sees everything -- Heimdall. Plus, the dude who guarded the gates of Asgard was one of Odin's most trusted. Doesn't it make sense that he would guard the Outer Gates as well? And this theory would open up the other possibility that since the Gates of Asgard open up to other worlds and realms (realities), that means they mighty also open up to non-reality. And that they're an Asgardian version of the Outer Gates themselves.