how does a knife blade made from an old file hold up, relative to the A2, INFI, ATS 34 ect. steel's used in 5 to 7in. combat blades? specificly, the prying or flexing strength. are these very hard to sharpen? how is the edge holding. I realize alot depends on the file steel used. does anyone have any specific expirence with Anza Knives of Santee? their spear point "combat knife" would seem to be a good project i.e. replace the laminated wood handle with micarta or something else, with a custom fit. what would be the easiest material to use to make a better handle (micarta, ?) I like the shape of the busse handle, but I know without the full tang supporting the outline of the handle, it would be a tradeoff. thoughts