I need information on an old Martin fireplace Model BWH-36. This fireplace has a heat circulation system,but currently none of the ducts or registers were installed. I have been looking for parts,but haven't found anything. I visited Martin Fireplace website only to find that they went out of bussiness in 2002. They were bought out and the current company isn't supporting any of the old products. I would appreciate any information wether it be a part source or alternate suggestion. Any information on the proper installation of said registers/ducts would also be very helpful!