It's a conundrum, theducks. Did as you instructed and no luck. The image and a trial line (The End) at the end of my practice epub refuse to centre. My headings do centre, however.
Tomorrow I will try another practice book from start to finish: TextEdit-.xhtml-epub all with: Title page with Heading, image and author name; a couple of chapters with Headings and a few lines of pain text; the final chapter finishing with "The End" and centred.
I like a good challenge but this is a little frustrating and I may just be making some simple wrong move I can't deduce. Clear head and a new project may work out. We'll see.
I appreciate your help. (This is the best forum I have come across with members who take the time and patience to help.)