Could someone please tell me what the key options are that I would need to get
the epubs from these pages?
I have tried dozens of times with the options I would expect but I just can't
manage it.

If someone could just 'shorthand' the list of options for me that need to be
changed from the default settings, I can learn from your advice.

Top page I am using to 'spider':
<https://web.archive.org/web/20191215153318/https://ebooks.adelaide.edu.au/meta/authors>

An example of a page with an epub (chosen from the first author and the first
book)- down the bottom of page:
<https://web.archive.org/web/20180314140724/https://ebooks.adelaide.edu.au/a/abbott/edwin/flatland/>

Another possible 'top' page I could use to spider from:
<https://web.archive.org/web/20191215153327/https://ebooks.adelaide.edu.au/meta/titles/A.html>

Given the way the net is going, I feel the need to save these books. The
original site was already closed down by a UNIVERSITY of all things. :(