there is a
thread somewhere, but does it really matter a whole lot? There is little to no difference in performance between a real one and a fake one. They are both cheap, with quality control being slim to none (does it look good and work before it leaves the factory? yes? then ship it).
having taken a REAL 510 apart, I can vouch for the sloppy soldering (I am class 3 mil-spec solder certified, and an electronics technician by trade). As far as the atomizer, it's nothing more than a nichrome wire coil with some fire-rope (used to line wood/coal stove doors) and a metal bridge.
Go with the best deal you can find, neither are complex, and both are considered disposable items.