In the (few) books I have, I found similar daggers only in a booklet by Hermann Historica, where they are called "Lothi" from Tibet. The furniture are similar to the ke-tri
http://www.aiusa.com/medsword/ethsword/tibet/index.html
Where might I found more news about it ? Above all, I wish to know why the cross section is concave/convex.
Any help will be appreciated !!!!
Regards
Paolo