This room would have been the main bedroom when it was a single house, I think; the back bedroom of the flat below was originally the living room, unfortunately doesn't have its original fireplace. But this house has changed ownership and purpose many times since it was built in the early 19th century; it was a school for physiotherapists during WW2, for example, and I think converted to flats when my parents bought it in 1948. I think the mantlepiece may have been covered even before that, but I simply don't know for sure.