Sterling, Harold: The Real Secret of Chalk Talk ©1958 (circa) Harold Sterling, De Voe - Sterling Company Softcover, stapled manuscript, 8.5x11" (when unfolded), 10 pages

Image courtesy eBay seller Mad-Collector

Comments: Illustrated with drawings. From the intro, "A comprehensive yet concise treatise on the art of Chalk Talk, Teaching the ins and outs so that almost anyone Can present this act with very little practise. Also revealing the real secret of learning to make the drawings and also how to fake it for those who have no natural talent for drawing."

Contents (based on Front Cover, numbers are not page numbers):

1 What To Use For Best Results
2 How To Build the Props
3 Where to Buy Them
4 Three Complete Presentations