Jeff Stephens' List would put it having been issued a serial number @ the onset of WWI and Lyund's list a year or two later. But the position of the >>Nitro<< Stamp puts it @ least @ the end of WWI if not in the early 1920s.
The Crown is either a Quality Crown or a Shooting Performance Crown. This one just might be the latter, where it was taken to the range & tweaked.
The Horn triggerbow guard is typical for cold weather environs and is quite common on inland Sauers.
Nothing short with anything about this Sauer.
from memory, if there are two crowns, one will be somewhat larger than the other....and i believe the smaller is the quality mark, and the larger is the one for shooting performance. in this case, i think the crown is the smaller version.