I'll bet the folks at the Walther Forum can help fill in some blanks for you.
I have pieced together some info regarding Walther introduction dates but missing some dates.
Please feel free to add or correct the following info. thanks.
1) 1929> Carl Walther manufacturers the model PP which has a 3 7/8in. barrel.
2) 1931> Carl Walther manufacturers the PPK which has a 3 1/4in. barrel.
3) Terms of surrender prohibit germany from manufacturing firearms. Carl Walther licenses french firm Manuhin in france to manufacture its firearms.
Year?, Models Manufactured?
4) Interarms of Alexandria, Virginia becomes importer. Year?,
Pistols Imported? from france? from germany?
5) 1968> Gun Control Act Of 1968 a.k.a. GCA68 prohibits the import of certain small sized handguns
of which the PPK meets the criteria that prohibit its import into the USA.
6) Someone gets the idea (Who? Year?) to put a PPK slide on a PP frame which enables this gun to be imported into the USA. this model is
named the PPK/S.
7) 1978> The PPK is manufactured in the USA by Ranger Manufacturer in Gadsen, Alabama, first in blue then in stainless.
8) Interarms receives licensing (what year?) from Walther to manufacture the PPK & PPK/S, first in blue then later on in stainless.
i am a little confused regarding the timing of Ranger and Interarms.
9) Interarms founder Sam Cummings passes away and leads to the demise of Interarms (year Sam Cummings passed away? and year Interarms went out of business?)
10) 2002> S&W becomes the importer of Walther Handguns. and will begin to manufacture the PPK in Houlton, Maine. Year?, I think the PPK/S was manufactured first and i dont know if the PPK was ever manufactured.
There you have it. just a partial history of Carl Walther handguns i pieced together from the web in a few minutes.
some info may not be correct and some dates are missing. please feel free to make corrections, add dates, etc.