Ever since moving into our late 1920s house, I've been perplexed by the fireplace and mantel. It seems to be a hodgepodge of different eras and I'd like to restore it if that is the case. The picture shows the lower half of the mantel which extends about six inches from the wall over the fireplace. The green brick is not actually brick, but some form of plaster. I've noticed that the spaces under both shelves (left and right) is hollow, but I haven't pried the wood off to see what's back there. My question is does this seem like it's authentic, and if not, how do I go about restoring it?