Thanks to everyone for kind comments.

I love this sewar too.
Hi Michael - I thought the classification would be based on the shape of the blade, and not really the size? I have another sewar of similar proportions, but with a plain blade and nice old patinated wooden sheath and hilt.
Hi Lew - thanks for pointing that out. However, I always thought the extra black portion of the edge, running from 30% up the forte to the tip was a sign of the tempering. The metal at the edge looked rather homogenous, except for the extra black shade, which turns out with etching.
Hi Mr McCormack, nice to hear from you. Unfortunately, kerises and other blades in the Southeast Asian context are often heavily etched, or even 'cleaned' with acid, resulting in rather corroded blade. Yes, the results can be quite upsetting to blade-lovers, but I guess that is part of the culture here - everything has a lifespan.