Hi, I have an 80s Townhouse with a fireplace that works well, but looks terrible. I'm going to clean it up the glass bi-fold doors and buy a new mesh curtain. But above the firebox, where I have the lever to open the flue, is a space with a couple of shelfs that have 1/4" of dust sitting on them. I can't figure out how to get in there to pull the dust out. In the picture attached, is that area above the box, that has the mesh-like screen in front of it. As best as I can tell, all that's in there are the two metal shelf areas, both with copious amount of dust sitting on them, and the mechanism to open the flue. Anyone know how get in there to clean?