[John Sabato]

Another give away on the ground rear toggle flat surface is the elimination of the graceful bevels on either side of the top edges which keep the part from being sharp... if these chamfers are thin or non-existant, the toggle has been ground flat to eliminate the manufacturer's mark.

The barrel looks to me like a portion of a surplus .30 caliber rifle barrel that has been fitted to the Luger and rechambered. The tapers are all wrong, and the front sight base arrangement is not factory... looks like it was slipped over the end of the .30 caliber barrel and soldered into place. A common practice for custom gunsmith Luger barrel replacement.

Your barrel dimension must be only the exposed part. You should measure the barrel by inserting a cleaning rod until it touches the breechface and then measure the cleaning rod that fit inside the barrel. Looks at least 7 inches from the photos and probably eight...