[fred cook]

Originally Posted by targa911S

Notice how even the hidden screws are timed perfectly. This is a high end gun.

Is that an "18" in a circle on the barrel in the 4th picture? If so, it could indicate an 18gauge bore x 2 1/2" shell which should come out somewhere close to the 11mm x 60mm mark. Whoever did the woodwork/inletting was certainly a master at his craft! I have seen this type of action before, but can't remember where or what it is. It will come to me eventually (maybe!).