Re: S&W Model 39
Well, no. It is true that the German P.38 inspired several designs of DA/SA auto pistols, and some aspects of the S&W Model 39 (and its successors) were derived in part from the Walther design, the two pistols are basically very different, and no one familiar with both would call the Model 39 a streamlined P.38. The P.38 uses a unique locking block system (later copied by Beretta), while the Model 39 is a cammed dropping barrel system using a basic Browning lockup with some variations.
The double action system of the Model 39 is also very different from that of the P.38.
One common, and positive, feature is the grip, which in both pistols is very ergonomic and comfortable. S&W got away from that, though, when they went to a large capacity magazine in the Model 59.