Yes, tests are always fraught with politics. The ultimate decision in 1955 was to shelve all effort and keep the 1911. 2.5 million of them in inventory was no doubt a significant issue. Another was that the pistol isn't considered an important weapon.
I picked up my copy of George Nonte's work, Combat Handguns, published by Stackpole, 2d Printing Aug of 1981. Lo and behold of course he describes the history of the 1954 Army Trials.
I paraphrase in my own words:
In short, Colt and Hi Standard jumped on the opportunity. S&W was reluctant as revolvers were their mainstay. The Ordnance Technical Committee released specifications in 1947 which included a 25 ounce weight and maximum length of 7 inches. Double action was required, in 9mm.
The submitted pistols from Colt included 9mm and .45 calibers, with early Commander style guns, the Colt T4, and the High Standard T3. They shared a large strap trigger guard that hinged for winter use. The Colt T4 has a particular style that could sell to this day. Hi Powers from Inglis were also submitted.
S&W changed course and submitted when C. R. Hellstrom was elected President, with Joe Norman lead engineer. The first prototypes were designatied X46, in 1948, with an aluminum frame delivered later in 1949. Original X46's had a grip angle of 25 degrees instead of the later production 15 degrees.
There were 31 X-numbered guns delivered up to 1954 in various alloys, steels, and features. After production started he notes there were 10 single actions made.
Wonder where those are today?
All facts are from Nonte's work but I accept any errors I may have introduced. Of the pictures in that portion of the chapter, there aren't any prototype S&W's, just one of a production model 39. He does go on to say that the model 39 has "the best overall design shape and sizing. Aesthetically as well as mechanically, it is a very pleasing weapon to handle."
I kinda think he was a fan.
I met his daughter in the 1980s serving as a LT, she seemed a capable and no nonsense type of person who would maker her father proud. George Nonte was quite the gunsmith, author, and retired from the Army as Major, Ordnance Corps. At the time he was already writing over 100 articles a year for magazines and publications, including his own books. As he was in the loop to some degree during his early career years it would go to being at least somewhat informed and more than capable of calling those in the know who could give relevant background information.
Just sitting there on the shelf, all I had to do was pick up the book. When doing historical research of that era - or anything pre 1999 - books are the norm and turning some pages is necessary. Goes to the lack of much about it on the internet. Perhaps some day when all the books in the world are scanned in we could do that, but it's going to be a long while. Like celluloid films time takes it's toll and we lose things making the transition.