An attractive and practical solution to filling in an old fireplace is simply covering it with some pressed metal panels!
Local clients of ours used just two panels (with left overs) of the Original pattern to fill in an unused fireplace in their living room. It stops the drafts and is a feature piece for the room. They left the panels in their natural, raw state for greater impact.
They could simply paint it down the track if they so desire. All our aluminium products are chemically etched making it easy for painting –see our Panel Coating Information here.