I think this is one for Bianchi Girl or Otis. I've had a few high-end Bianchis from 77 to 86 but I'm not sure about this. The Campy dropout has a hole for a Portacatena which was introduced in 1977 and the BB cable guides look later than 1980. The B panto on the fork bridge is impressed and under that horrible white paint might just be chromed. Reparto Corse models after 1978 had "Bianchi" panto stamped top of the seat stays apart from a 1982 Specialissima Campione del Mondo a friend had. Wild guess says 82 Campione. Check this link Bianchi Specialissima Campione del Mondo 1983?- speedbicycles.com. Also looking closely at the seatpost, it looks as though it is older than the frame and it is stamped 27.? Are you sure about the tube diameter?