a 0,71" Schlussspiegelpatrone, SN looks like 6702
this is one of the late made - this means after 1870 - special order double guns shooting a real needle fire paper cartridge
dont think the blueing is orignal but none the less its a guns I have an interest for myself.

and a very late hammerless 20 ga
to bad the serial number is not visible but I will try to investigate it
you will see the barrels dont turn to the right side anymore but move forward and break very similar to the Collath guns. this Gun must be made between 1890-93 and 1899 and a lot of things were changed but it still have the Dreyse DNA.