The RZM PPKs were prized bring backs from WWII because of their connection to the Nazis. They are mostly middle-1930s pistols. The SS-RZM above is quite unique. I believe Zipperhead sold his a while ago.
Sadly, our PPKs are not going to go South in the near future, as Kidvett says, they fail the BATF minimum standards. Simpson and others are importing plenty of wartime PP pistols (they seem to have dozens of Zella-Mehlis .22s) but any WWII PPKs are either pre-1968 or smuggled.
Our American friends won't even take back their own pistols and revolvers that "do not meet sporting needs", such as Colt and S&W snubbies and old autos. They will accept some of our prohibs as antiques, but those are pre-1899.
We do have 12(7) here -- a blood relative with a regular R-PAL can receive one of these Zella-Mehlis (pre-1946) pistols. They are not all destined for the smelter, unlike their newer brothers made in Ulm, or assembled in France by Manurhin.
There are quite a few RZM PPKs in Canada, and thousands of Zella-Mehlis PPKs (pre-1946), but I haven't seen one for sale with the SS serial numbering or the excellent condition of Zipperhead's pistol, even in collection catalogs. If you have one like it for $1000, let me know!