Hi All,
A couple of notes: Yes, shuriken are an old weapon.
Classical Weaponry of Japan by Serge Mol have a number pictured (including one on the cover), and interestingly, they don't all look like the modern six-pointers shown. Many schools seemed to have their own "signature" throwing weapons. This book is also neat for the number of old Japanese weapons. Many of them I've never heard of (or seen) elsewhere, but I think that they're simply unknown outside of Japanese museums and collections.
Anyway, while shurikens are old, I'm not sure the same is true of the "ninja-to" (straight bladed wakizashi with a square guard). After all, if you're a spy/terrorist/infiltrator, why run around with a sword that instantly identifies you as such and is difficult to hide? Check out the
Wikipedia article, which suggests that the ninjatos that are everywhere are a modern invention. I'd love to see an old ninja-to that matches this description.
my 0.02 cents,
F