I don't have the 1961 version but AFAIK it covered associate figures only and did not include the Cha Cha which was still to be adopted by the dance world.
The 1964 edition, published by the Dance Teachers' Association, included all five latin dances up to Fellowship level. It was derived from Laird's articles in "The Dance Teacher" October 1963 to February 1964. It was a small book, more descriptive in style than we know today, reminiscent of Alex Moore's books of the time.
By 1972 the Dance Teacher's Association had added the word International to their name to become the IDTA, and the green book was published in tabular/chart format. No photographs yet so everything had to be described in words including the extra details on use of arms etc.