it looks to me like the stock cover, custom made like the one in your photo!
i remember a thread back a while mentioning that he send his stock cover to someone and made it custom.... hope that helps a bit
i remember seeing probably the same thread with a DIY jobby too, but methinks this cover is milled aluminium-- take a look at the light reflecting off the main face of the cover (2nd pic), it's got a radial shine to it...