very unique brass covered Dreyse double gun http://egun.de/market/item.php?id=5612918
think its very old for dealing with a broken stock not nice but useful

SN looks like 7893 what makes it a pre 1870 gun. very unusual cartridge designation " 16,6mm J.Patr: 16,6mm" - Jagd Patrone = Hunting Cartridge 16,6mm ?
anyway, I think its one of the Randschlussspiegel needle fire cartridges but maybe they thought for a whil to change the inch caliber designations into metric.

the stock still have the old tip for holding the cleaning rod so its some kind of a transition gun.

same seller have a beautyful 1865 Jäger rifle for sale. this is reason we call it the good old times
http://egun.de/market/item.php?id=5612938