A couple comments.
Post WWII Germany was prohibited from small arms production for a decade and in 1952 Walther arranged for Manurhin to make the PP under and PPK under license in the Alsace region of France (basically Germans in the an area France acquired after WWI). The Manurhin made pistols were imported to the US by Tholson in 1953 and from 1956-1984 by Interarms. In 1968 the PPK/S was added.
Once Walther was able to make its own pistols in Germany it still had Manurhin make the slides, frames and small parts for the pistols, but had the slides delivered to Walther unfinished, where Walther had the slides induction hardended, roll marked, blued, assembled and inspected by Walther. That was enough under German law to qualify them as "German made". These pistols often stand out as the Manurhin and Walther bluing is usually a slightly different shade with a resulting slight mismatch in the colors.
Walther continued this arrangement until 1986 when they discontinued the arrangement with Manurhin. Walther made in Germany not withstanding, the quality of these all Walther made PP series pistols took a slight drop, as Manurhin made a superb pistol and it took Walther a while to get up to speed.
10-12 years ago very good to excellent condition surplus Manurhin made PP pistols were being imported at prices around $400.
Manurhin ended its arrangement with Interarms and started importing its PP series pistols directly from 1984 until 1986 and that prompted Interams to arrange to acquire the license for US manufacture and distribution of the PPK and PPK/S, which resulted in the Ranger marked PPK and PPK/S pistols.
I have owned a few Ranger made PPK/S pistols and have found them all to be good quality, although they can be picky about hollow points.
I greatly prefer the Ranger made PPK/S to the S&W version. The Houlton ME era S7Ws were nothing but a disappointment with a couple recalls and some pointless changes made by S&W such as minor dimensional changes in the grip frame that complicate grip compatibility, and worst of all the extended tang. It does arguably reduce hammer bite for modern shooters who think they need to use a high grip, but that tang is sharp, poorly sounded and digs into your side in IWB carry.
S&W may or may not have fixed the mechanical flaws but I won't buy another as long as it has the extended tang with its crude, cheap to make sharp edges.
Interarms also hedged its bets by ordering the steel frame commercial FEG variants of the PP and PPK/S - the AP9S and APK9S in .380 ACP and the AP7S and APK7S in .32 ACP.
The slides and grip frames are slightly larger on the FEG steel frame commercial pistols, as the design evolved from a PP clone redesigned for use with 9x18 Makarov.
Interams imported them to a very high standard of polish and finish (the AP9S and APK9S above compared to a TGI imported APK7S below) intended as a a replacement for PP series imports if they were not able to arrange the manufacturing license. But they sold well and were a less expensive alternative so they kept importing them until they went out of business in 1998-99. You could still occasionally find them new in the box until around 2010-2012 for around $350-$400.