Hey that's a nice Epub! Can it get any better? An advanced guide to Epub editing!
Q: How can I use an Image for a Chapter heading (an image saying "CHAPTER ONE", and have it show up correctly in the Table of Contents (in text, as "CHAPTER ONE")?
A: You can put anything between the heading tags to make Sigil link to it in the NCX, and set the "title" attribute on the <h#> element to get the text.
So, "<h1 title='CHAPTER 1'><img ... ></h1>". The TOC would link to that heading element (and by extension, the images inside it) and the TOC entry would say "CHAPTER 1".
(from
https://www.mobileread.com/forums/showthread.php?t=59619 )
Q:
A:
Q:
A:
Q:
A:
Q:
A:
Q:
A:
Q:
A:
Q:
A:
Q:
A:
Q:
A: