Ennio's ink falls into what I call that "scrawl" category, but that aside, the M, usually consistent in signatures acquired in person, appears malformed, out of character, in comparison to one I have (in person signing) and a few I've seen that I know were in person signatures. The whole signature appears to me to be an abbreviated version.
I found this. Very similar to one i have. Book suposed to be authentic. What i'm trying to say, it seems like my probably authentic too:-) I'm sorry about my poor English, pals:-)
Ennio has had just about as long a career and of signing for fans as anyone. He's one of the 20th/21st centuries greatest composers. It would be interesting to assemble a comparative study of his verifiable signatures representative through the decades.