Regular Luger and Artillery Lugers

[Johnny Peppers]

But they were issued and in permanent use on the (short) P08 with German Police Forces in the years after WWI.

PS
Is there a case on record of a North American citizen being prosecuted for attaching a standard issue stock to a P08 (`Luger´)? Or is this just another ludicrous case of jobsworth one upmanship?

I'm sure you have references to the German Police Forces permanent use of the shoulder stock in the years following WWI?

I have absolutely no idea whether there is a record of prosecution on attaching a shoulder stock to a "Luger" (all Lugers were not P.08's), but that has absolutely no bearing on whether it is law or not.