::sigh:: Try “Milanese Rite” because it is the Rite of the Archdiocese of Milan (not just the city). It was the rite of Pope Paul VI, as I recall. I think it involves a litany chanted by a deacon, special symbolic gestures, the Creed AFTER the Offertory, and a couple differences.
Now, the rite itself has a different calendar.
I have NO IDEA WHY, but as a youngster, our parish had the Ambrosian Rite Mass ONE TIME (to be nice to a visiting priest, or because Monsignor got it in his head it would be a good idea, who knows). We were told to be there (it was the 60s- we were there), and to follow along as best we could. The new altar facing the people was down and the old altar was used, a shock. Portions of the Mass were out of place. There was an extra reading besides the Epsitle and the Gospel. A really huge procession was made with the bread and wine at the Offertory, which wasn’t exactly an everyday event at the time. And there were a herd of priests!!!
Can’t help you more than that. You can Google, too.