This old photo may be of interest (not mine):
http://www.flickr.com/photos/flanifo...7605415600743/
Notice the man on the left 'fingering' the blade - explains why the blades are left unsharpened for the first 1/3rd or so, and gives some insight into the style of swordsmanship used. Maybe it's well known to others here, but I just stumbled across it today.
Best,
Iain