I have just made some myself after 2 years of nagging. They fit around a recess on either side of the fireplace and are painted the same colour as the walls, if I copld find out how, I would post a photo for you.
I used 2"x1" timber screwed around the wall and screwed mdf top and bottom then iserted some 2"x1" supports in the middle and capped the front with slightly ripped down 3"x1" routed with a bevel finish. Filled and sanded all the screw holes, decorators caulk round all the edges and painted.