The chassis was started years ago by another builder and was included in the book "Building the Climax" by Kozo Hiraoka on page 90. A partially built third truck was included with the project. The chassis was built using drawings from "Building the Climax" doubled in dimension.
The drawings in "Building the Climax" first appeared in Live Steam magazine.
I have admired the three truck Climax design by Bob Reedy that was presented in Live Steam magazine between July/August 2001 and November/December 2004. After acquiring the chassis and boiler I decided to finish the locomotive using Bob Reedy's design.
I am not aware of a source for prototype Climax drawings.
The book "The Climax Locomotive" by Thompson-Dunn-Hauff has some drawings of Climax locomotives and Climax logging cars. These are just outline drawings, not plans to build a complete locomotive. However, the book is a great source of prototype photos. The book is out of publication but copies can be found at used book stores and eBay. Highly recommended for the Climax enthusiast.
The book "Climax an Unusual Steam Locomotive" by Taber and Casler is a source of prototype photos, but no drawings. I have only seen the reproduction book, quality of the photos is very poor in this book. I would not recommend buying a reproduction unless you want to read the text. Better to save your money and buy "The Climax Locomotive".