Sorry about the late response, forgot about it. Found the info on brightness control in some thread on the raspberry pi forums which I found through Google. I can find it now tough, the threads that show up in my browser history only talk about the file that lets you turn it off/on. Obviously the brightness control works though.
Was baffled when there seemed to be no way to control the brightness (I did not check FAQs for that before buying, being able to control brightness of a display just seems like a given).
Turns out it's possible but for some reason isn't documented in an official capacity anywhere which is just bizarre. Your FAQ is one of the top hits on Google when it comes to the display so seems like a good place to have the info (also bought display from you).