Aha again!
I shall give the zipped-file thing a go. I ran half a dozen or so html ebooks through the html2lrf engine last night (command line, of course) and they all worked pretty well. The only downer is that I now have half a dozen perfectly formed ebooks, all called "index". Whoopsies.
Tonight I shall have another go, probably with more reading of the documentation.
Thankies
Cdr W "The Pig" Piggly