The problem with your research is (as usual) you are ASSUMING things you flatly don't know, and did not bother to find out. Specifically, whether or not the degrees/requirements have CHANGED in the time period between 1975 and today. The Italian comment I quoted says specifically that they HAVE changed, and that the degree that Rossi has was, at one time, the highest degree offered at Milan, but is no longer so. That commentor doesn't get into specifics as to what current degrees/requirements are. And in fact your own U. of Milan link ALSO says that the university made major changes in degrees and requirements in the 1990's, but doesn't give specifics as to what things were chaned FROM.
There is no indication that Rossi's degree isn't perfectly legitimate for the time and place granted. Other than, of course, your imagination.
Except for that creepy letter that conjures up memories of Rathergate.
Plus, if I should need to document my PhD, I request copies of my transcript be sent; I don't ask for a letter stating the degree I received.I suspect the letter shown is a fake. The letter shows oddities: the font size changes for no discernable reason, and even though it is not right justified, there are variable gaps between words.
There is no indication that Rossi's degree isn't perfectly legitimate for the time and place granted. Other than, of course, your imagination.
Your problem is that you want so badly to believe that Rossi is genuine that you're willing to overlook just about anything that contradicts that belief.
So what if the Italians changed their laws specifying requirements for a degree? It's highly unlikely that such changes were very substantial as far as actual work required for a given degree. I especially doubt that the requirements for PhDs were made MORE strict than when Rossi supposedly attended university.
It also doesn't help your case to quote an Italian as saying that until 1986, the highest degree offered was a Master's. That is, in effect, saying that it was impossible for Rossi to even get a doctorate.
Last, I will reiterate that the degree Rossi claims to have earned from the U of Milan, the "Dottore Magistrale in Filosofia", is a Master's degree in Philosophy. It not only is not a doctorate, it isn't even a science degree. I don't know about you, but I've never dealt with philosophers in the lab. It appears to me that the specific degree name was selected so as to convey the impression that Rossi has a level of education that he does not; the Italian words for "Master's degree in Philosophy" sure do look like the English words "Doctor of Philosophy". Too bad (for Rossi) that we have Google and can check these things out.