The wallpaper I had used before was a low-resolution printout, just to test. I have now printed it out properly - it comes from Jennifer's printables, which is a terrific resource. First, I changed the wallpaper on the chimney breast, which I then pasted on the wall. Then I hung the wallpaper on both sides of the fireplace. I used lining paper to make the bottom panel.
I first planned to attach a wooden dado rail, but then I remembered the 1:1 wallpaper I had used to make the fireplace so I found it and made the rail to match the fireplace. It was much easier.
There is a deliberate gap between the wallpaper and the ceiling where the cornice will be added. The floor is temporary.
When I have gone that far I realised that I needed to finish the rear corridor before it was sealed off. It isn't as crucial as in the basement because there is a back wall I will put in last of all. Still, I wanted to test what it may look like. I had by chance placed the Chippendale chest-on-chest in the rear corridor, and it immediately felt perfect (I have tested other pieces, and none felt as good).
I had not thought about the colour scheme of the rear corridors because it had felt less relevant, but in fact it is about time. So I tried various coloured paper and wasn't happy. Then I found some sheets of old wallpaper from the Victorian living room. It is worn out, and I would not use it in a front room, but for the rear corridor it was fine. Of course, no one will ever see the reverse of the partition once I have sealed the back wall, but for my own satisfaction I wallpapered it. I may even put up some pictures which no one will ever see.
You cannot see it very well in the picture, but there is light in the rear corridor, and when I have fixed it properly, I am sure it will look great.
Next, I made the side wall, pasting the wallpaper onto the white lining paper and adding the rail. When everything is properly fixed and finished, the ceiling painted, the floor put in, the doors painted, etc - I believe this will be a very grand room.
It took me two evenings, about six hours altogether, to make these two walls.