I googled George Formby's signature ad they all looked like this one. I saw several references to "George Formby Signature Banjos" which leads me to believe that he signed a certain number of them, and then they were sold. I am sure some of our English brethren can enlighten you further.
That's one of the series of John E. Dallas and Sons Formby "Signature" ukes. The Model A, in fact. Nice uke - thousands were made - everyone of them has a Formby signature rubber stamped on the vellum and lithographed onto the headstock logo plate. Beginners' model worth about 100 pounds. This is WAY overpriced.
Wait for a Dallas C or D, and expect to pay between $300-and $900 depending on condition.