Ah-ha, I stand corrected, the firearm is Nitro proofed. On the left barrel, next to the powder and bullet weight and type is the crown over N for Nitro proof. That sort of surprises me given the size of the firing pins. Speaking of the firing pins, the left one obviously has either a broken or very tired retracting spring. They are easily replaced with a simple ink pen spring. Just experiment to get the correct length by cutting off coils until it's correct. The crown over W on the shotgun barrel denotes it is choked but what degree is never indicated and, the circled 16 I expected to see, for the era, means it is chambered for the 2 1/2 in. hull. The crown over S is simply the proof mark for a shotgun barrel.
OG is correct about the sleeved hole in the top of the comb. I am going to differ with OG regarding its value. Honestly, in my experience with old German drillings, I would double his figures. While it's obvious the piece is not pristine it would benefit from a good, gentle cleaning and I believe that would greatly enhance its appearance, thus value. The other thing is you have the scope and rings. The scope might not add much, unless you have priced vintage German scopes on evil bay or anyplace else you can find one and, depending on who made it. To have the claw mount rings duplicated would cost about OG's estimate of the value for the drilling. My experience in fooling with those old German firearms is if you can find a drilling like that, with scope and rings, for 800 to 1000 you better buy all you can if, as OG mentioned, it is in decent condition. About 3 months ago I worked a trade on one not too dissimilar for what amounted to $1900 and the guy was tickled to get it for that.
Edit: I have to stand corrected again. The numbers beneath the type of powder the gun was proofed with are the weight of the shot charge in grams, not the weight of the rifle bullet. I apologize for the confusion. Given the appearance of the muzzles and that the checkering of the forearm is still mostly intact I don't believe that piece saw much use after the gentleman immigrated. On many of those the checkering on the forearm is worn smooth from carrying while the checkering at the wrist remains quite nice. I have several in exactly that kind of condition.