I have a Temco prefab fireplace with a hole in the refractory panel. The previous owners burned wood, but maybe they wanted to convert it to gas? Not sure why the hole
Wood Burning Fireplace 42" WRT4500 G42 Superior FMI Custom Georgian Indoor Fireplace WRT4542 F0628 F0629
Craftsman - Astria
a plus, inc. - Superioir Fireplace Refractory brick
MC Refractory | Information
Superior - VRE4542 42" Fireplace, White Stacked Refractory Panels - VR — Fireplaces USA