I researched Ishi back in the sixties, in high school. Glad to see it's not been forgotten. It's an amazing story.
You might like this guy's site, then. Here are some casts and photographs of Ishi's work (be sure to check out some of the non-Ishi stuff too... like some of the woodland cache blades from Illinois and the incredible posters this guy puts out ) :
Lithic Casting Lab