This bayonet was designed to be used as either a bayonet or a sword, depending on the requirement at the moment of need. It is basically the Austrian Model 1849 Augustin Jager Carbine Sword-Socket Bayonet but with the Lorenz helical mortise slot.
They were manufactured from about 1854 to about 1867 and were used on a carbine or short-rifle, not a full-length musket.
It is believed these were used during the American Civil War when many European arsenals were emptied of their surplus arms.
They use a leather-covered wood scabbard, sheet-steel mounts (not shown).