Got One

[JBBOOKS]

Hey guys I took the advice many of you offered and bought a shooter grade Luger as my first gun. The Luger is a mismatched pistol with the upper matching. The frame, side plate, and grips match the frame number. The internal parts match the upper. The frame is stamped on the left side with 7 4 W and the right with a B. The grips have to be removed to see this. Can any tell me who made the frame and who made the upper? The acceptance stamps on the right side are marked 655. The magazine is marked 122 37 on the side. I think the holster is made for a HI Power because of the markings WaA101 nka43.
I paid $750 for the gun and holster. How did I do? Any information you can give me on this pistol would be appreciated.