All right, so for the list of changes… the back leather pieces is a lot narrower, I’ve removed the rounded corner which looked dumb and moved the small strap edge almost edge to edge of the back piece. I also changed the angle where the two pieces meet because 90° was just too extreme and unnatural. Then there is the back ring stuff.

Pro tip, the Blender bolt generator plugin makes some nice rivet heads with a flattened top… aaand it’s pretty quick.

I got some good feedback on the pillowed aspect of the inside so I’m keeping it for now.