I just bought one of the Gold Marc Inserts that are pictured on this forum. I slid it into my late 1980's Heatilator type fireplace without any problem. My primary question(s) relate to the fire box. I have the bricks that came with the unit and they are put in the bottom of the unit. There is a second and less wide set of steel ledges above the angle iron where the top of the bricks are positioned. My unit came with some type of a sliding shelf that is inside the fire box. What is it for and where does it belong? The guy that I bought it from had it on top of the angle iron and said the guy that HE BOUGHT it from said that it was to help with smoke to not come into the home. This shelf was lying on top of the angle iron at the top of the bricks. With it there the burnable area is GREATLY reduced to at least half. That's why I'm wondering if it can go higher in the firebox and does it have to be used at all ?? One of the pictures here showed a thermometer on the surround, Is that really an accurate way to measure the temperature. I have a terra cotta lined flue that is at least the 8 x 13 size. Where can I get the fireplace screen that goes infront when the door is open? My damper handle DOESNOT have the decorative brass ball like the photo, is that a special owner add on?