Re: S&W Model 39
I said above that there is a lot of confusion about that whole group of S&W autos, but I would not depend on an auction site for accurate information. The Model 44 (so-called) is even more confusing. It really was the first to be announced, in 1954, and appeared in the 1955 Gun Digest. The cover has a picture of an engraved model. It has no model designation, and is described simply as the "S&W 9mm pistol". There were similar articles in the gun magazines at the time, all describing the single action model.
The DA model (later called the Model 39) was actually produced later. It shows signs in design of being the result of a "crash" program. The SA gun was made in only a small quantity (100 or less is the usual figure given), though it was cataloged. The clamor for the DA model apparently led S&W to drop the SA model and concentrate on the DA model. Even so, it was some time before any appeared. Mine is #5683 and was bought new in 1957. It has an alloy frame.