Someone at p38forum.com might have the data you need.
Walther arms Ulm/Donau, Germany
You will need to contact Walther to find out.
1931 to date
You will have to contact Walther for the exact date.
The Walther PPK pistol was first released in 1931. During that time the Walther PPK pistol was popular amongst European police and civilians because it was reliable and concealable.
The PPK/s is a PP with a PPK slide.
No published sn data for Interarms PPK
Made in 1939.
The Walther PPK pistol is manufactured by German small arms maker Carl Walther GmbH.
Impossible to answer without the serial number.
I believe you are asking about a Walther PPK/S made by Umarex. I would contact Umarex directly and ask them at Customer Service. See the link below.
In the first film, Doctor No, it is made clear that Bond does not prefer the Walther PPK as his weapon of choice - he prefers the Beretta, but is overruled by his superior, M.