I have a soft-spot for Japanese + Italian bicycles. My Univega Super Strada with Campy Super Record fits this bill. Anyway, I think my affection comes from the fact that they're so unique. Each Japanese manufacturer usually only had one model like this, and it was always what they considered "top of the line." I haven't seen this Nishiki before, but I was eyeballing a Nishiki "Ultimate" some time ago that had a full Campy groupset. I hope this works out for you and please show it to us once it's built up. Cheers!
-Collin-