Here's a thought. The Hearth Model does not completely hide most fireplace openings. There is a large gap below the feeder blower motor. I did not mount my Coal-Trol on the hopper as it is kinda ugly. Instead I placed it a couple inches back from the fireplace face brick and fed the feeder blower & feed mechinism power cords thru a tie down that I fastened to the bottom left rear corner of the hopper box. I then used the ash pan /door cover as a screen that covers the opening in the fireplace below the Hearth model hopper.
So now my fireplace opening is pretty much totaly coverd except for about 1-1/4 inch on either side of Heath Model.
Now for my suggestion. Why not paint the door / ash pan cover to match the Hearth stoves and suggest that it is also be used as a screen to hide the fireplace hole below the feeder mechanism. I'm going to get some Stove Bright black paint and paint mine ASAP. It will look great .