I am sorry G, I didn't know you had posted 6 days ago.
The Crown over U is a visual inspection. Crown over S is merely for a shotgun. Crown over W means it is a choked bore but the degree of choke is never shown. The 16 is obviously the bore size and the circled 16 means it is chambered for 2 1/2 shells. The "NITRO" in block letters tells us it was proofed in Suhl. Those proofs tell us it was proofed between about 1900 to perhaps shortly after WWI. The first German proof law was 1891-93 and it was revised in 1913 but was not fully implemented until after WWI as that conflict broke out in 1914. Hubertus is the trademark of Immanuel Meffert, a highly respected maker whose shop I think dates back to either the late 1700's or early 1800's. Meffert could be considered the Joseph Manton of Germany. That is from the proofs off picture 9 in your first post. That firearm has been re-blued as the barrel flats are always left in the white.
The pictures of the entire guns, even blown up as far as I can blow them up, are too small to tell much.
