Hello there! Thanks for all the help you guys provided, I will consider acquiring a 3D printed rail (heck, I might even make a grip like the one shown by Samurai above if I find somebody with a 3D printer nearby) since I have a specific grip that I want to attach.
Also, Jamsandwich, that's one sexy AUG you got there.
EDIT: Quick fyi: I am not living in UK.