What a lovely attic room. We had two like that in our house in Hobart. The lining boards were Baltic Pine and had originally either been sealed with shellac or left bare timber. One of the two rooms was still lovely aged timber but someone had painted half the other room white. Such a shame. Some of our lining boards were warped and twisted like that too, though other areas were perfect. Our attic rooms had the chimneys coming through the middle of them - also covered in lining boards. Very quaint - especially as one of them opened onto a third floor balcony with a castellated stone parapet.
Its good to see you are doing such a good job with this house. That stair decoration is very pretty, perhaps Gothic revival as was common in the Picturesque Style common in the 1890's. Is that the date of the house?