Wow, nice bike. I wish I could find a Nishiki frame (25") to repair the 84 Oly 12 I crashed in February. For now I plan on doing a similar kind of transplant with the components from the Nishiki onto a frame from a 23" 1984 Schwinn World Sport.... but I've had the Olympic 12 since it was new and it kind of breaks my heart to think I won't have a Kawamura-built frame anymore....
I like the job you've done, and don't worry 'bout that chain; I understand that's the new fashion trend.