T-Mar - here is the info on my Nishiki Olympic I noted in another thread.
Serial number - GM740607
4130 Dbl butted CrMo tubes
Shimano SIS derailleur and shifters with biopace chainrings
Shimano brakes with aero levers SLT?
Araya 700c rims with Joytech hubs
The color is a medium blue with white seat tube and headtube insert.

I'm guessing maybe 1987 or 1988. Let me know what you think.
Thanks