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: