Bookshelves modified, painted and reinstalled
The three bookshelves did not quite fit. I modified one (the one on left of entrance - face-on in the first photo) by making a rebate (10cm by 15cm) from top to bottom, so that it fitted behind the middle bookshelf. The three bookshelves were three different colours, so I repainted two to match the middle bookshelf, which was the best quality of the three - solid wood, not melamine coated chipboard.South - 1 resize.jpeg

Painting involved sugar soaping, sanding and special priming of the melamine with tile & laminate primer. One bookshelf (the cheapest) didn't take the primer well, and I ended up abandoning painting after completing one panel, as it started to look like a psychedelic painting from the 1960s (Martin Sharp I'm not!), and then I resanded it hard to get adhesion.
Looking north (to the back of the recess - rotating 180 degrees clockwise from first photo). Bookshelves painted and reinstalled.jpg It's a very tight space, so photos are hard to take. However, it's just for storage and you can move around quite sufficient for what its use is. I can see how Harry Potter found it hard living in a spandrel!