Originally Posted by
satbuilder
I did some research a while back, I had purchased a Bianchi, which was being sold as a "Team" bike. Had the full Campagnolo Record group. Seat lug had the 173 stamp.
Somewhere, and I don't remember where, now, I read the 1XX stamp on the seat lug indicated it was a top level frame, whether that meant team, pro, or Specialissima, I'm not sure. But it did mean it was their top of the line frame.
Here's mine:

You have one beautiful Bianchi! Thanks for that information regarding serial numbering and significance. It does help me feel even better about the Bianchi I have now. It would be nice knowing that it is a top of the line model. I have had a couple of Italian top of the line bikes from the same approximate era, including this wonderful 1969 Atala Professional that I restored and sold years ago...
And now, in addition to this Bianchi, I have a sixties something Torpado Professional that will go into the stand this summer and, hopefully, be restored along with the Bianchi(have to ride the Bianchi before deciding if I want to restore it or not). I have already ridden the Torpado Pro and am more than satisfied with the ride quality...