Just re-read Preface and Chapter I of "Parabellum is back 1945-2000" (just ordered such a pistol, not arrived yet). The book explained the exotic word "Parabellum" -- it's DWM's brand name. To promote this brand, DWM adopted it as the company's telegraph address. Make lots of sense.
Bought the pistol, partially because it worked great in my memory, partially because I have this book
Reading a gun book without a sample in hand is a little bit boring..