I just recently picked this bike up for $40, although I've replaced lots of bits that were broken. It has Shimano Light Action aero downtube levers and shifty bits. The shift cables are routed over the bottom bracket. The serial markings are, as far as I can make out,
G0286
6121723

I'd love to know more about the frame. I've yet to find a picture of a 1986 Nishiki with aero levers like mine.