Ken,
Bob Lum was the first designer and maker of the American tanto.
The word Tanto in Japan refers to a specific length of edged weapon of about between 6 and 12 inches.
In that blade length I have seen examples of many types of blade shapes and types including full double edges and triangular in cross section armor piercing spikes.
Many traditional tantos have very simple clean blade designs.
Here is one by the bladesmith and friend of mine Michael Bell of
http://dragonflyforge.com/ who lives here in Oregon.
I'll call Michael later and ask If I can post this here.
The Tanto is for sale.