Project Aon has all the Lone Wolf books in a variety of formats, including a machine readable format, which they have used to produce similar diagrams of the books' structures. Joe Dever have them permission to distribute the books for free some years ago (you can also now buy them as ebooks, I think). They're all at https://www.projectaon.org/

SVG flowcharts of many gamebooks including FF and Lone Wolf: http://outspaced.fightingfantasy.net/SVG_Flowcharts/main.htm...

FYI Project Aon have mapped their structures, for example: https://www.projectaon.org/en/svg/lw/01fftd.svgz

The differences are interesting, like which are more linear and which are more branching; some have relatively early choices that fork into two long separate branches.

The other day, I found out that those are freely available nowadays. Somebody even made them into an android app (also free).

Those were awesome.