Where can I get information about the FAA "restricted like" license to fly a N aircraft in Italy / Europe?
I don't know what an FAA "restricted" license is, but I guess it may be a foreign-based license issued under 14 CFR 61.75; see this answer for more information.

It's an FAA private license that's linked to your Italian one and it gives you all the privileges of a regular FAA private license, including operating N-reg aircraft anywhere in the world. But note that if your Italian license has more restrictions than the FAA one (e.g. no night flying) then you still have to obey those restrictions.

The process to get one is described here but I believe you have to physically visit an FAA office in the USA to get it.