The centerpiece of this fireplace mantle is polished concrete. It's fine but I need to fix the ugly sides, and do it "right" which means it should be an inexpensive fix that would blend with the centerpiece which is 2" thick. The space that I need to fill on each side is about 12" long by 6.5" wide. Can I find a brick or paver of this size, or slightly smaller, so it would not require cutting, which could be attached to the fireplace and the centerpiece with mortar? Checked the local HDepot but didn't find anything fitting.