When producing any part or machine, it’s important to have all the same parts be 100% interchangeable. To produce a truly repeatable part, there has to be standardization of that part. To do this, typically a drawing is created. On this drawing is placed dimensions, and more critically, tolerances for each surface and feature of the part. This book studies the tools that help a machinist achieve these goals. The gages detailed in this book were found in a scrap yard in New York. Painstakingly the author cleaned and preserved them before starting to unravel the number codes and identify their use. Each gage was photographed in color and pictured in the book, often with line drawings of the part each gage was developed to produce. This was a labor of love by one of the countries foremost authorities. Also included are observations about the Thompson no other person can equally expound. All machine gun enthusiasts, Thompson owners, and machinists of all types will find this book fascinating. 8 ½ X 11, soft-cover, color photographs, illus, 419pp. For those wanting more information on how to build a Thompson see the Machinist’s guide to the Thompson Submachine Gun elsewhere on this site.