montana girl, that book is a classic and you were very fortunate to find it for sale as it is no longer available. Another company acquired the rights to the title and the use of the late Dr. Walker's name, but they have heavily modified it and it is a poor substitute for the original.
Dr. Norman Walker lived well past 100 years (some accounts say 107 yrs, others as high as 110) and passed away during either the late 1980's or early 1990's to the best of my knowledge.
Anyone else looking to purchase Dr. Walker'sbook should ensure that it is the edition published by O'Sullivan Woodside Co. That is the authentic version.