If the DiaCompe brakes are original, it would seem it is an '85. From what I saw in the pictures, 85 would be about right for that bike. My wife has one that is an from somewhere between 85 and 87 and it has the same types of components on it. In fact, it has LePree components, which I haven't seen on bikes newer than that (but doesn't mean there aren't). My wife's bike also has a name badge which although not identicle to yours, is different from the older Nishikis. My wife's bike is also the exact same tubing and the lugging looks the same, so I'm guessing it was built by Kawamura. I'm not sure where Prestige fell in the Nishiki line. A search of the forums would probably reveal that, or I'm sure someone will proffer that information. I'm guessing it fell in somewhere in the middle to upper mid-range area of Nishiki's line.