A bit of a disappointment, to be honest. Back in 1976, the final pair of Gilbert & Sullivan operas were thoroughly obscure, with neither receiving any professional productions outside of the US in eighty years (as far as I'm aware). For the D'Oyly Carte Opera Company's centenary season in 1975, London audiences had been able to see Utopia Limited for one week and The Grand Duke for one night only in concert. So Wolfson's book was timely to explore these works in full.
Fifty years later, the works have a place on the fringes of the repertory, and are beginning to attract more companies to experiment with them, albeit with both usually requiring significant rewriting and pruning. The full libretti, contained herein, are available easily online and in better volumes such as Ian Bradley's annotated edition. Wolfson explores the origins and creation of these works, which is still valued information, but he also sees a lot in the works that I do not, in terms of his view that Gilbert and/or Sullivan had reached a point where they could no longer hide their excoriating attacks on society. That conclusion doesn't work for me, where I instead see two men who were no longer able to interact politely but were both driven on by their own personal ambitions and demons. As a result, a significant chunk of Wolfson's content here simply isn't rewarding. I recommend the numerous biographies of the men and the better overview volumes I've reviewed elsewhere.