These illustrations are based on the diagrams from "Sobotta's Textbook and Atlas of Human Anatomy 1908", the copyright of which has lapsed. The source files were obtained from wikimedia commons, and are listed below. 

The images have been edited to remove labels, change contrast and slightly tweak some details. In some instances more than one image has been combined (for example the cut-away views of the insular cortex). 

Source files

1. insular cortex: https://commons.wikimedia.org/wiki/File:Sobo_1909_633.png
2. lateral brain: https://commons.wikimedia.org/wiki/File:Sobo_1909_626.png