T-Mar, I looked, but I can't find any markings on the bottom bracket. Maybe I'm not even looking in the right place. The dropouts say "Suntour GS" so you're right there. Did any Japanese brands use Falk tubing? or could the "Falk SL 66" sticker mean something else?

While looking around on google I did find one bike that looks pretty similar...
http://www.fixedgeargallery.com/2005...ky.htm#image_2