This is a great cookbook if: you have access to a good butcher or meat-counter to obtain the various kinds of poultry and meats/sausages (squab, sweet italian sausage, salted pork, liver, veal knuckle, beef marrowbone, etc) called for in these old-school Italian recipes. As a native new yorker, and an Italian, I had heard about the history behind this book and I enjoyed reading the 14 paged foreword which explains about the Leone family and lists some of the famous people who used to dine in Leone's kitchen. There is an insert about mid-way through the book with black and white photos of Gene Leone, the author, and his mother, Truman, Eisenhower, and other US notables.
However, be forewarned that the recipes in this book call for gargantuan quantities of butter and oil --my arteries nearly clogged just reading the required ingredients. Thankfully, using non-stick pans, I have managed to prepare various meals (about 5 so far) halfing the amount of butter and oil called for, and so far, my family and I have been extremely happy with the results.
I recommend in particular the champagne and truffles spaghetti sauce and the sliced filet mignon in red wine.