P-1 is actually post WWII version of P38, with aluminium frame and, according to some posts, with some kind of steel inserts used as guides for a slide. I think that it was used mostly by police.
The main reason I am responding is to make you aware to shoot in P1, P38 and Lugers 9x19 ammo that is for the pistol ONLY. Any attempt to shoot hot, high pressure submachine ammo will wreck noted pistols in short order. If I got it right, for that reason (at that time in W. German) Army used some other, stronger pistols. Hope that other, more knowledgeable members could tell us more.
Despite I really like P38, because of that ammo issue, I do not want to have any 9x19 pistol that cannot shoot full power 9x19 ammo.