Firebacks have been around for a long time. They serve three purposes - they absorb and radiate heat back into your home making it more efficient, second, can be used to hide a dirty or damaged back wall, and third, they can add another layer of charm to your decor.
If you use it to hide damage, be sure to fix all cracks and/or replace any missing parts. This is not a replacement for the back wall. Safe-T-Boots (feet) are available to position the fireback how you want it.