My Penguin paperback edition of this novel contains a dedication by Wodehouse "to Douglas Fairbanks, who many years ago played Jimmy in the dramatised version of this novel". The novel first appeared as a Penguin book in 1991. It's original publication was by Herbert Jenkins Ltd. in 1921. So it's not obvious which edition Plum wrote the dedication for.
As other reviewers have pointed out, A Gentleman of Leisure is a fair rework of The Intrusion of Jimmy, which dates from about 1910. So the story ran from novel to stage (screen?) and back to novel. It also interestingly foreshadows many of Wodehouse's later devices that would become hallmarks of his (seemingly) effortless style. What's really lacking in this book is Jeeves, who of course had not yet shimmered in at this early date. While the pieces of the plot would reappear with countless twists, here's early evidence that he could write a really good love scene. Later, he'd back off a bit on such vignettes while beefing up on the stock characters. The overall effect is to render this a book for Wodehouse completists, which heralds glad tidings of things to come.