some resources for a bianchi
We don't usually supply lists of resources here, because they don't really fit with the general SE question-with-one-best-answer approach.

Interest in retro bikes and cycling gear is at an all time high, and so is the amount of information available.

I'm answering because I hope to give you, and others who end up here, an example of how this information can be found

In this case I Googled "1981 bianchi catalog" (press enter after following the link) and got a bunch of hits.

The best seemed to be Bianchi 1981 Catalog. It should answer a lot of your questions.

Many old catalogs have been digitized and can be found in a similar way.