Hi i currently live in a victorian house that has a marble mantel piece in one bedroom and a slate mantel piece in the other.Unfortunately neither has the original victorian insert,so i want to replace them with originals that i have bought.Neither fireplace will be used as a working ,it will be just for appearance.I believe it is not a good idea to try and remove the mantel pieces as they are likely to break so i intend to leave them as they are.Please therefore could somone give me some advice re installation.Many thanks john