The chisel-point thumbnails thing is pretty common among old Filipino street-fighters, BTW. You see it a lot among the old escrimadors in areas with large Filipino communities here in the U.S. (like Stockton, CA), usually accompanied by a big heavy stick that is nominally used for a cane. These are guys who used to fight to the death with knives or sticks in the old country, and looked for an advantage in any fight, hence the thumbnails. I think there's a close-up photo of one of their thumbs in Dan Inosanto's book Filipino Martial Arts
"Flow with the Go."
- Rickson Gracie