Very funky pistol...one of the Big Three to come out of the West German police pistol trials in the early 1980s. The same trials brought us the HK P7 and the SIG P225. The P5 is basically a beefed-up modernized Walther P38 with a redesigned slide.
Peculiarities: It ejects brass to the left, and has a heel-mounted mag catch. Single operation lever, which decocks the gun and operates the slide lock.
I don't ever see them used anywhere, but I've seen them online for quite a bit over $500. I'd probably pay that much for one in good shape.