Zoejory sounds like our last house. Large late Victorian semi. Staircase boxed in, all the doors had sheets of hardboard on them. A large, and presumably, lovely marble fireplace was removed from the living room and replaced by a 1960s tiled fireplace, marginally btter than the 1950s 6 inch beige tile monstrosity we had had in a previous house.
We know the living room fireplace was marble and lovely because we still had its twin in the dining room.
We now live in 550 year old listed building, renovated and restored in the 1960s, the nadir for old house restoration, but our predecessor was thoughtful and careful. One or two things we wouldn't do now, cement based plaster and all the old floors replaced by a concrete slab, but otherwise pretty good. It is the perfect Christmas house and we celebrate in our 15th century house, full of 19th century furniture in a suitably Dickensian fashion.