nice double gun, SN looks like 26201 http://www.gunsinternational.com/guns-fo...un_id=100825076

"Dreyse Needlefire System Side Opening Needle Fire Shotgun. The bores measure to 18 Gauge a 16 Gauge shell will not fit to the chamber. This one is circa 1862 or so. The action functions well with a lefecheaux style lever that moves the barrels forward and then to the side for loading. The action is fully engraved with open vine European style engraving, double triggers, horn grip. The barrels are 32" when measured from the back of the chamber, steel, clean bores with light pitting ahead of the chamber. The stock is in very good shape with a cheek piece, nice chequering"