If you're talking about the little thing on the side of the barrel? Then I've already cut that off. It was the main reason why I hesitated to make it in the first place, until I got another AUG to butcher another front off.
Looking at this picture, I don't really see the vents, they could be there, but I haven't seen any good pictures yet. I'll try some real steel forums later and see if anyone has anything.
And if you only want a thread for looks, and not to use, then I could probably do it, or at least get close to the look.