Hello Kevin -- and a warm welcome to the forum (with apologies for being a bit slow in coming here to look at your message).
As you have read in the two old posts you cited, Heather and I both saw the online text of the book as posted by Grant Salisbury in his Salisbury Genealogy
pages, hosted by AOL in the section of their site devoted to user-generated web pages. As you will also have worked out via your search engine, it very much looks as though (for whatever reason) Grant never moved his material to a replacement webhost in the way advised by AOL -- and it therefore all seems to have been deleted without replacement. I have failed to find any alternative online version, e.g. via Google Books or the Internet Archive, though conceivably you and I may both have neglected to put in the right search terms to bring it up. Nor can I instantly spot a postal or e-mail address for a (Yorkshire-based?) Grant Salisbury -- though Facebook users might, I suppose, find some way of contacting him via that site. Heather did have an e-mail address for him once upon a time, but I think she said that it had gone AWOL.
In hardcopy the book is certainly rare: for instance, the UK's principal copyright library (the BL at St Pancras) does not seem to have a copy, and nothing came up for me on WorldCat. The copy that I have used in the past is the one held by the National Library of Wales, so if you are within reasonable range of Aberystwyth that is probably the best way for you to gain access. If the NLW option is impractical and you want information just on the passage in Chapter 8 dealing with the authors' own branch, do get in touch with me via this site's personal messaging (PM) system and I'll see whether I can help you out. (N.B. the forum software will deny you use of the PM facility until you have made one more post on a public board [e.g. "OK, I'll send you a PM"])
Thereafter, little green scrolls (lit or unlit) should become visible to you under other posters' names , and you just need to click on the relevant one of those to bring up a text box for your message.
Of course if any other reader of this thread finds a new online copy of the book, it would be great if they would let us all know.