Since I think we are going to use our insert without the surround, I can't just put the mantel shield behind the surround, so I need to mount it to the inside of the fireplace opening, which is a foot above the stove. However it's got a metal lintel (very thick steel or iron) on the bottom side of the brick, and the back side of the lintel doesn't seem to have anything to clamp onto with C-clamps or anything. I guess I could drill brackets into the brick along the sides to hold it up? Any other suggestions that would not require drilling into the masonry much?