You're gonna love this, Stratty.
There's a free programme called "HTTRack" (or WinHTTrack for the Windows version) that enables you to very quickly copy a general website (or a subdirectory) in its entirety (it won't work for ESMB!). The base URL for the book is
http://www.xenu.net/archive/books/isd/isd.htm. Choose a "base path" (where on your computer you want to save it, like C:ESMB/goodies or something) and then paste in "http://www.xenu.net/archive/books/isd/isd.htm" as the URL to be copied. Leave all the confusing default options as-is, press start or whatever it is, wait a minute, and Bob's your uncle!
Paul