Thanks T-Mar! The seatpost diameter is an even 26.0mm. The rear derailleur is Positron FH-400. I scoured the derailleur and could find "FH-400", "Shimano Japan", "VIA", and near that "HI". Any help?

As far as it being a subcontracted, European market model, does that mean anything special about the bikes original quality (low-end, or perhaps more middle of the road?)? Of course, at this point, this bike is nothing of it's former self. Having been converted in its entirety to Campagnolo with a brand new, sealed bottom bracket, 8-speed set up, and many more modern amenities! haha

Also, did you all post somewhere here, some type of collection on how Bianchi's serials work? I'd really appreciate looking at that!