Hi. Being my first post let me start by saying what a great site this is. Unfortunately I haven't been able to find a good answer to my question. I have a 10 yr old prefab by Superior. The back metal panel in the firebox has a crack down the middle. I guess the old homeowners would toss wood in there like they were pitching a baseball. Do I need to replace it or can it be sealed with cement? The crack goes from the top to bottom of the back panel but I'm not sure how deep it goes. If I replace it should I buy the one from Superior which is very expensive, or buy an aftermarket one that needs to be cut to size? Thanks in advance.