Melody Lowman

Our fireplace is missing the covers to the heatalator fans. The fireplace is made of native Texas limestone and the fan outlets are at the bottom. They are 12inch. by 9inch. opennings and the prvious owners must have “eaten” the covers/vents. We would like to replace them with something attractive such as cast iron or black metal. Can you suggest where we might find such a thing?? Thankyou, Melody