Jamie,
Mr . Gillespie is right,it would have been 1850 NCO pattern sword.One thought it could been captured.It is is very good sword.I hope you get more details on the markings.Not to change the subject, but I seen Cavary sabres cut into side knives.I have a T A Potts bayonet that was supposely made in New Orleans ,with the barrel rings cut off to make a side knive.