This book will not help you to learn to play like Formby - at best you will learn to accompany Formby songs. The problem? Well, Formby had many Ukulele Banjos tuned in different keys. The authors of this book have transposed each song to a common tuning. But the chord shapes you play are no-longer suitable for playing the chord variations that typified Formby solos. I struggled for four years with this book before working out that what was written down was not what Formby was playing, and it delayed my learning of the Formby technique for that long too. If you want to learn to play like Formby, join a Formby appreciation society and get some instruction from a fellow plucker - to date, I haven't seen a good George Formby music book.
Happy plucking!