I took ownership of my first Nishiki in 2007. It's a 1985 or 1986 Prestige, and definitely "Handcrafted by Kawamura."
My coworker has a Prestige, but a different year. I also own a Nishiki USA Backroads mountain bike.
Surrounded by all these Nishikis made me curious - so I started a website. Right now it's called Nishiki Bicycle History. I'm attempting to document all Kawamura factory-produced Nishiki bikes sold in the United States.
If you would like to contribute, please email me, email@example.com. You can contribute by emailing me links, photos, personal anecdotes, or by getting a login to the site and updating pages. It's wiki-style so it's really simple to create and edit pages.