This link takes you to a pdf file of a scanned copy of a photocopy of the original Lucas Book. Over the years I annotated a photocopy version in pencil so now in some ways it is more useful than if I did a fresh nice scan of the book. This version has been kindly rescanned by Andrew Daviel, who is a relative descending from Phebe Lucas and Thomas Glaisyer, of Brighton. See p. 15 of the Lucas Book.
The layout of the book follows a traditional style for a presenting a genealogy, and it works very well once you get used to it. Unfortunately when there are large families it gets a little confusing (very confusing!) because there can be gaps of several pages between children in the same family. After a while even that gets easier to follow because of the system of indenting each subsequent generation.
“Our” Lucas family starts on page 16, the descendants of John Lucas and Judith Marsom.
In general I’ve found the information to be surprisingly accurate except for the initial page and the first part of page two. Those pages are more difficult to really verify and so far I haven’t spent much time on that part of the whole project. I suspect that as more material becomes available online and indexed it will get easier to sort it all out. In the meantime it is very long ago and I’m not going to worry about it.
In the end it would be nice to see if it would be possible to hook up some other Lucas families in different parts of England, and I can see that possibility with the increasing use of DNA for genealogical purposes.