The history of climbing tools, and the pioneers who first figured out how to climb more difficult and wild climbs with them, are available in print form on Amazon and Blurb.
Links for Mechanical Advantage: Tools for the Wild Vertical
AMAZON.com
Volume 1 (mostly European developments) : https://www.amazon.com/dp/B0CGZ2S58J
Volume 2 (mostly USA and global tools): https://www.amazon.com/dp/B0CH26LTFM/
BLURB.com
Mechanical Advantage, Volume 1 ($25) Best color version: Volume 1: $42
Mechanical Advantage. Volume 2 ($30) Best color version: Volume 2: $58