I am almost sure that it is an '87 Nishiki Sport: Came with Araya wheels, CrMo frame, Shimano LA DR's - basically a decent UJB that would be worth ~ 150 fully reconditioned. - A LOT less sans wheels.

In my experience the SIS is not so good but with friction DT shifters and those Light Action DR's you have the makings of a pretty nice road bike. It was built for 27" though, so I don't know what that means to having any brakes on a 650b. (Personally I'd take the 27s over 650 all day long.)