As mentioned below, I located a copy of this work recently and promptly ordered a copy. It arrived yesterday, and after an initial perusal during my lunch hour I am pretty impressed.
The book contains two different indices for every article published in either the Cavalry Journal or its successor, Armor Magazine, from 1888 to 1968. It was compiled by Walter E. Young and edited by John J. Vander Velde. Every single article published during that period is referenced by Author and by Subject/Title.
The scope of the work is very impressive, doubly so when one considers that this was compiled before the availability of computers. The editor states in his preface that this was done by index cards, one article at a time, then cross-referenced onto other index cards.
The only downside of the book that I’ve noticed so far is that the Subject/Title index may take some digging to find what one is looking for. This isn’t that difficult, however, as one simply needs to check several keywords until the right one is found. In the editor’s words, “In formulating the subject headings based on keyword approach, it was constantly kept in mind how users of this volume would most likely extract information.” If one knows the author, there’s is no problem at all.
Overall, I think this is an excellent work. It serves as a great link for directing searches of existing collections at places like USAMHI at Carlisle Barracks. For those of us who employ researchers to gather information for us by proxy, it is very valuable.