German p-35 hi-power

Just recently purchased a P35 FN Herstal from a veteran who brought this pistol back from WWII-- Wa 140 s/n 150690 all matching numbers except for the magazine that has JI on the bottom. My guess is an Inglis magazine??? Where can you get more information on this pistol--date of manufacture, etc. I am trying to collect all the weapons of WWII except for auto's and ones I can afford heheh. Should this pistol have a s/n matching magazine and also marked Wa 140? Thanks David