I have a pretty large fireplace that is a little odd in some ways. Has a metal floor that dumps ash to the basement clean out. A big metal plate in the back. I was told the brick isn't "firebrick". The opening in front is 48" wide by 36" high. It is 28" deep at the bottom, but 19 1/2" at the top. Here are some pictures to help. I don't like when there is some surround that covers the stone, so I like a flush look, or just go with an open fireplace, but they are wildly inefficient. Ahren-Fire was proposed by two companies if I want an open fireplace. Approx $9k US. I certainly feel I could line this myself and get a mason to fix issues, but no firebrick? Any ideas? I like clean and more modern, but the fireplace itself isn't "modern" looking.