A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Frank Reed
Date: 2020 Sep 4, 16:57 -0700
"Can anyone share a pdf copy of that book on Heath Sextants - "My Modern Sextant (notes on how to know and how to handle it)", G.A Heath, Heath and Company, 1937"
I haven't seen a PDF of that booklet. If I'm not mistaken the message you found it referenced in is fifteen years old --a very long time for hobbyist websites like the one where it was previously available! There are a couple of hardcopies for sale... Was there something in this book you were looking for?