On Wed, 27 Dec 2017, Jürgen Spitzmüller wrote:
You did not yet tell us what you actually want to customize, but I was referring to \chapterformat, for instance.
Jürgen, I thought I had written of my desire to learn how to create the equivalent chapter headings using KOMA-Script as provided by fncychap. When I read about \chapterformat in the English translation of the book I found how to change the number of lines in the chapter heading (1 or 2), the numbering scheme, and use (or not) of a prefix line. I'm not enough of a LaTeX-pert to see how to use these to make a fancier chapter title than the default. I do have fncychap working and I'm back to focusing on the book's content. Best regards, Rich