Adventures in Renovation

Tonight I smashed the bump-out walls upstairs. These are the same walls that I wanted to turn into built-in bookcases (if I had all the time in the world). After the electrician took out the bottom portion it seemed inevitable that I'd have to redo the whole wall. It would be hard to try and match the old plaster with new pieces of drywall. Also I'd have to strip the old wallpaper off and fix the holes and broken corners that happened when I took down the wood paneling. Or just smash it and rebuild it fresh. Plus, now I can air seal the top portion where it meets the ceiling. Otherwise, air could still leak from the attic down into the walls.

It seems that the brick chimney doesn't run all the way up. Now that I'm looking at it taken apart, I'm tempted to leave it this way to some extent. Maybe build a small wall a third of the way up to close in the electrical and vent and leave the top open. Then later I could build a bookcase in this space. Maybe I'll just leave it open and then I can make a decision later after I live with it a while. Any suggestions?