This is a very interesting sword, and the third I've seen with such a mounting mechanism displaying what appear to be dragon creatures.
It is in fact Korean and likely of the later Choson Dynasty.
All three I've seen are of court level manufacture and display a number of interesting characteristics indicating the quality of the sword.
First, of the three that I've seen, including this one, one had a Japanese blade.
As the Koreans borrowed a significant amount of specifically their sword aesthetic and decoration from Japan (though there was cross-pollination across the strait as well in both directions), the use of Japanese blades is not to be considered a non-Korean trait.
This blade I believe is Korean by the form and style and the fuller, which though found on Japanese swords does not end in the manner seen on this example near the tip of the blade. It is possible that the blade was ground down over time and the edge specifically, but I would bet this is Korean workmanship.
Second, the use of the rawhide style work on the handle in imitation of Japanese tsuka wrapping is also indicative of Korean work.
Third, the mounting mechanism is purely Korean but an interesting interpretation of the way that Japanese tachi are mounted with a purely Korean form of attachment through a spring along the spine of the scabbard that inserts itself into the crossguard.
A wonderful sword.
We sold one with a near identical mounting mechanism.
It can be seen below.
http://armsandantiques.com/exception...wungeom-cs1051
We also have a number of articles on Korean swords as well describing their debt to Japanese workmanship but also the innovation in some of the decorative flourishes and aesthetics.
http://armsandantiques.com/3-joseon-...-19th-c-cc1252
http://armsandantiques.com/5-joseon-...ca-1800-cc1254
http://armsandantiques.com/1-joseon-...ca-1800-cc1250
Hopefully folks find these useful.
Regards
AAA