I am NOT a professional historian in any way. I have though, studied the European fascist movements since I was young, I am now 29 yrs old. I have also relatives from Italy that were in the army (and later partisans) during the war and experienced Mussolini's early and later rule. There existed military persons in Italy which had some kind of rank and some official leadership roles whose names are not on google at all. Maybe not a general or something so decorated, but yeah. I too have read this letter and I wonder what makes you think it is fake? If so, faked by who? There is a classic infamous ustaša NDH story too, that an italian journalist (I think?) visited Pavelic, and in his office he had a basket full of human eyes that Pavelic's ustashas had given to him, this person wrote later. Some U.S general had a pencil holder made of a Japanese desecrated skull, so it is not impossible that this didn't happen, but it seems also a bit fake if one look into the story. Maybe it's the same with the letter you mention. The ustashas and black legion were psychotic in their killings, but stories about postwar ustashas going through airport securities in Europe carrying cut off bodyparts in their bags and so on are most likely fake.