You left out Cliff Edwards and Lyle Ritz, PHJim.

And, not to put too fine a point on it, but, though George Formby did play the ukulele, mostly, he played a Ludwig Banjolele, which doesn't even really look like a uke.George Formby's Ludwig Banjo Uke

At the bottom of the page is a picture of another very famous George, holding Formby's instrument. Not surprisingly, most of his music sounds pretty good when played on the uke, too.