Rollin left a comment on "A Blast From The Past":
Your readers should know that numerous Will Henry and Ken Harding books are available in electronic form from olympiapress.com for the princely sum of $1 each.
Following up his tip I did a Google search on the site looking specifically for Will Henry and Kenneth Harding.
Some of the hits contained excerpts, so if you are interested.
Confessions of a Spankee by Kenneth Harding.
Suburban Spanking by Will Henry
Modern Spanking by Will Henry