My uncle, Thomas Ramage Ethridge (now in his 80s and living in Oxford, MS), who has the publication rights to "The Ethridge Family & Allied Kin" has given me the OK to scan the publication and post it on a website. As soon as I can find my copy (in storage) and scan it (with a new scanner I'm about to purchase), I will make the link available to this forum.
My grandfather, Wm. Nathaniel Ethridge II, gathered the data, wrote, and published this book. (A few other forum members have copies of it.)
Unrelated: I discovered some time ago that U.C.S.D. (La Jolla, CA) has copies of a number of original folios of Sir George ("Easy") Etheredge/Etherege, a Restoration poet/playwright and contemporary of John Dryden. See my posts about 3 years ago for more information on Sir George--a very interesting fellow whose most famous play was "Love In A Tub."