Some years ago, I saw someone make a barrel shroud for their AR-10 they called "Project Titan." It was mostly for looks, and I wanted one.

While I was at it, I tossed on a hinge for kicks. I might've also been borrowing from the Toha Heavy Industries 4000XL from Biomega.

For the hinge, I used a 0.25in aluminum bar. You'll probably need to drill the hole out and it'll still be tight, but that's not necessarily a bad thing.

As for the mounting lug, I'll be the first to say it's kind of buggy. If you have a better idea, I wouldn't fault you for trying that instead.