617 Squadron, if I remember correclty, skipbombed the Roer Dams, and sank the battleship TIRPITZ using “Tall Boy “ bombs. So they had the expertise. But that being said, why would Harris want to kill Mussolini instead of Hitler? Easier to hit Bertschegarten, and the Chancellory, and Hitler was a much more important target than the “Moose”.
Hitler was doing far too good a job making the Germans lose the war faster than they would have done if someone with a less dogmatic strategic mind was in charge.
An SOE plan to assassinate Hitler, called Operation Foxley was abandoned for this very reason....