Re: 16gauge/7.7mm double barreled shotgun/rifle value?
"Lauf" just means barrel.
The rifle caliber is probably 8.15x46R, but we would need to see a good picture of the markings under the barrels to be sure.
That type of gun is called a "drilling", the German word for "triplet", for obvious reasons, and it appears to be a very nice one. What appears to be the shotgun safety on the top behind the lever is the selector for the rifle barrel. The safety is on the left side of the grip above the triggers.