Though it is not very clear in this shop, I have added the second press stud on the extreme edge and started to form the shape of the zip elements. I also changed the tone of the book cover slightly to give it a more even coverage of paint tone.
The real sunlight is casting a ray of light across the bottom left of the painting which 'washes out' the tone of the paint on the edge of the canvas, but that is the nature of my studio in the mornings.