Wow, you guys are really helpful! Thanks so far. The fork blades are oval, not round. And yes, it has internal cable routing to the rear.

So what you both are implying so far is, that it might be an old bianchi?

Here comes some more photos:

foto 3.jpg

foto 1.jpg

foto 2.jpg

foto z.jpg

I'll get back with the measures of the bb later