My home has an open brick fireplace in the living room. It looks cool but it's not very functional. The one time I had a fire, a non zero amount of smoke came inside the house, so it's not really worth using without fixing the damper which I don't want to do right now. It has an old throat damper that is quite rusty and barely works.

I'm losing a lot of heat here as this is in the same room that my mini split heat pump is in, which is my main source of heat. I'm going to use some foam boards to close it off, but I want to do it in line with the outside wall, not above the fireplace because there would be a lot of heat loss through the bricks in the back of the fireplace as well. What could I put in front of the foam that wouldn't look awful?