Kabal: How about post-WW2 .380 PPKs which were inscribed "Made in West Germany"? I would like to look up the time span for this production.
Unfortunately, I am not familiar enough with the American market to tell you anything about the PPK's value. Here in Germany, post-war PPs and PPKs are common and inexpensive guns.
I'm sure others can tell you you what different versions of the PP series are worth in the US. You might also check gunbroker for completed auctions.
I can't really answer your question about the production span of the .380 PPK marked "West Germany" either.
What I know about the production span of the post-war PPK in general:
From 1952 to the 1970s or 1980s, PPKs marked "Ulm" were "pre-produced" by Manurhin in France and then finished and proofed in Ulm. They were marked "Made in West Germany" from the early 60s.
I know that Walther produced the PP in Ulm in the late 80s after the contract with Manurhin expired, and I guess that they also produced the PPK... which means there might be some PPKs marked "West Germany" made in the late 80s.
I don't know when exactly they started or stopped producing the PPK in .380 though. I found a list of serial numbers, but only for the .32.
The best place to look for this kind of infirmation should be the Walther Forums:
http://www.waltherforums.com/forum/...-pay-how-much-worth-questions-start-here.html
My impression is that they were issued to police (only in the Bundesrepublik?), but what approx. value do they have if in excellent or near-mint condition?
I'm not aware of any police agency in Germany adopting this version. As far as I know, both German police and the Bundeswehr (as P21) adopted the PPK in .32. The German police then switched to 9x19 when terrorism became a problem in the 1970s. I would be rather surprised if another European country's police force used the PP or PPK in .380, although I can't rule it out.