Here is the post card again.
And here is part of John Perry's email.
The postcard on your HAT posting of 27th February is, indeed, the English 'wonder' performer Little Cliff.
He was 14 years of age when he toured the Rickards theatres in Sydney, Melbourne and various parts of NZ in the second half of 1906. I imagine the source you found giving his age as 4 years old had dropped off the first '1'!
Little Cliff (proper name Clifford Perry) rebranded himself as Laddie Cliff the following year, when he started touring the United States. He went on to become a big star of vaudeville in US and UK in the 1920s and '30s.
He was my late father's first cousin. The family ostracised him for both going on the stage, and divorcing his first wife; both were shameful acts in those days! He died in 1937 without issue.
I also found the autograph below in my collection.
Many thanks to John for contacting me and for allowing me to reprint part of his email.