I was hunting for a place to read 'The Facemaker' online after hearing so much about Lindsey Fitzharris' work on WWI surgery, and honestly, it was trickier than I expected. The book itself is published by a major house, so the usual free PDF sites felt kinda dodgy. What worked for me was checking my library's digital portal—Libby or Overdrive, depending on where you are. They had the ebook and audiobook versions, and the waitlist wasn't too long. It's the most legit way to get it without paying, especially if you're just curious about the medical history angle and don't need to own a copy.
If you're open to buying, Kindle or Google Play Books are straightforward. I ended up getting the Kindle sample first because the prose is so vivid and graphic; I needed to see if I could handle the descriptions of facial injuries before committing. It's totally worth it, though—Fitzharris makes the story of Harold Gillies and the birth of plastic surgery read almost like a thriller. Just a heads-up, some of those archive photo sites that come up in search results have excerpts, but they're often incomplete and the formatting is a mess. Your best bet is definitely a library app or a mainstream retailer.