I have a copy of Vanderlinden's book on FN Handguns, but won't be able to check it till later this evening. My guess is that magazines with serial numbers matching the pistol would be desirable and add some value to the weapon. The Hi-Power was used all over the world, but the "authorized" series of German Police Pistols as my limited understanding was: P1-was essentially a P38; the P2 was the Sig P210; the P3 was the Astra; the P4 was a P38 with an alloy frame and slightly shorter barrel; the P5 was the Walther P5 (ejects empties to the left) ; the P6 was the Sig P226; the P7 was the H&K squeeze cocker. That pretty much exhausts my limited memory.

I'll try to check the book this evening, unless one of the more knowledgeable folks here chime in.