10 "fishscale" Celluloid inlays. Inlays shrink a bit but do not rot like tuner tips.

11 nut is industrial nylon material. This nut is likely not original. Anyone who seriously plays a guitar for any length of time probably (99% definitely) goes thru a few nut changes. Notice paint on brass truss nut and half moon washer.

12 Frets generally medium and not to wide. As with nut, any guitar this worn should have had a fret job or two. This one has.

15 headstock is a standard shape but varies slightly. Each started quite sharp but the finish sanding/shaping makes some slightly wider/narrow than others. Hand finishing brings variation especially on the "moustache" wings. Some tips are sharp while others get rounded as you see here.

16 Headstock angle is always the same. This is a clean factory cut.

17 neck shape varies but again overall consistently follows a general standard. The basic shape was cut on a shaper and then a human finished the neck on "deadhead" belt sander.  Thus a general spec was in mind but thickness and feel does change piece to piece. Necks are carved from a solid one piece mahogany blank. "Wings" are added at headstock for required width.