This has been an interesting and enlightening thread. For what it's worth, my ca. 1981 tre tubi Bianchi (see signature) has the following attributes: 1) under bottom bracket shift cable routing; 2) single set of water bottle bosses (downtube only); 3) no pump pegs; 4) recessed brake mounting nuts; and 5) two-tone gold-over-red drop shadow "stick" type BIANCHI decals on the downtube and seat tube -- no chevrons.

Actually I would have to say that the seat post is 27.2mm. I just didn't have a set of calipers handy so I used a ruler. It was just wider than 27mm so 27.2mm sounds about right. It sounds like everyone has had some fun trying to figure this one out. I am very greatful for your interest as well as seemingly infinite knowledge! I have always been very curious as to what this bike was since I bought it about 7 years ago, but no one seemed to have an idea beyond the Bianchi stickers.

So I suppose I'll advertise this as a mid 80's (1984 likely) Campion d'Italia.

I agree. An Italian built 1984 Campione d'Italia seems to fit the bill. I place much confidence in T-Mar, Otis and John E's opinions as they carefully consider their responses and have much knowledge.