Thanks Spunjer - I was asking about the fuller/cross-section because it is something I have seen on just a few blades (one of which I used to own). I was thinking this "step" to the back edge might be a specific to a region, but so far I really don't know...
Old Bangkung/Bolo(?) with what I believe might be a similar cross section:
http://www.vikingsword.com/vb/showthread.php?t=6271