I use Drillaud's sweet vermouth. This brand makes an excellent cocktail, and on especially hot days, I add a squirt of fresh orange juice and a generous peel

I've been replacing the club soda with tonic water. It's sublime

I've been replacing Yellow Chartreuse with Benedictine D.O.M. and Creme de Violette with Creme Yvette, and I've found it's just as perfect with those modifications

Excellent! I find that an extra 5 mls of amaro and 2.5 mls of luxardo maraschino cherry syrup make a superb addition

Small note—should be "Nouveau Carré", as adjectives defining the beauty, age, number, goodness, and size of an object go in front of the noun.