Antique Cast Iron 19 3/4" Fireplace Heater Hood

Vintage cast iron fireplace/heater hood. Measures 19 3/4" x 10 3/8" x 4". There are 2 bolts on the back that measure 15" apart and 2 holes that measure 17 5/8" apart. I'm not really sure what this is, but it's some kind of hood for maybe a ceramic heater in a fireplace??? There is a 1/4" slit across the opening where it's like a flue for ventilation. I bought this at an estate sale, therefore I don't know the age or history behind this beautiful piece. Very unique and would be a beautiful decoration. There is a crack on the one side and a piece chipped off but it doesn't seem to interfere with the integrity of the piece. (see photo). Photos are of actual item to be bid on.