Not a Bianchi expert but the decals do point to 1989 while the components do not. 1989 Campione D'Italia used Cromor in a Superset configuration. But it did not have Shimano 105. It is possible that it was sold as a frameset and the purchaser chose Shimano 105 to dress it out. Cromor is OK, not as good as SL or SLX regarding weight.
Everyone has different ideas on fit. I agree that it appears to be too small for you. That is a very aggressive position. Maybe OK if you intend to race, but it makes my neck hurt just looking at it.
But I'm older now.
Congrats on your acquisition!