unusual Vietnamese / Chinese sword in Japanese style 19th century

 An interesting south asian sword, probably Vietnamese, unusually made in the Japanese style or a mixture of forms. The good steel blade is slightly curving and swept back in the style of early Japanese medieval blades, with a fuller along the back edge of both sides. The handguard is in typical tsuba japanese form of bronze in high relief of scrolls maybe waves, possibly with inlay. brass blade mounts also. The grip of cylindrical form, srwapped with rattan, and originally lacquered black. Good but worn condtion, the pommel with an age crack to the wood, small section of rattan missing. 89 cms long in total approx. 19th c.