The Frame has the full Serial Number, the Slide, and Barrel/locking Block have the last three digits on them. With the BW Stamp, does that mean it was in the W German Army?
With the exception of the Bw, the gun looks all-original.
At least following Dieter’s timeline, it’s unlikely to have been a Bundeswehr pistol. Until 11/63, the NATO supply number was supposed to be on the right side of the slide. Also, the official stamping didn’t start until 1963 and was rendered as two capital letters, BW, until 1977, when it changed to Bw. So someone must have decided to bubba this onto the gun long after it was born; whether that was a German army armorer, I somehow doubt based on the amateurish appearance. But anything is possible.
Since the gun has the circle-with-dot mark and what appears to be the two federal quality control eagle-with-drooping-wings marks, it was a service pistol. My bet would be on a Bepo or BGS (Readiness Police or Border Police) gun; I don’t trust that Bw.