M1859 (?) Officers sword
This is a tough one to crack! The model 
is seemingly just about the same as the Swedish M1859, but the Norwegian swords of this kind came earlier, a number of these have Oscar I’s monogram – and he died in 1859. This one is even more troublesome as it has the Norwegian lion from before 1844 on the blade. That should “prove that the saber is from before 1844, but that is highly unlikely.
These sabers were for the most made various places in Germany, some by CP Larsen in Sweden and my “private” theory is that somebody screwed up and put and old lion on a new blade – some time in the 1850’s. There is, of course, also the possibility that an old blade from the 1820s or 30s was mounted in a new hilt. Anyhow, I prefer the old lion, so it is completely ok with me.
The “Type 1859” is not a model, it is more like a family of swords from a period. Norwegian officers wanted smaller and lighter sabers and these were the solution. Most come with a straight blade, some are slightly curved like this one. Most have brass hilts, some are silver coated. Some have etched blades, most a not etc.
Click the pictures to enlarge them.