I now have Tempus Fugit Creme de Noyaux and can say that subbing with amaretto will be noticeably different. Not meaning bad, but definitely different. One change I did make, after seeing the comments by several Discerning Drinkers regarding the closely related Lily Cocktail, was to replace Lillet Blanc by Cocchi Americano. This probably resulted in a more flavorful, bitter drink, which we both enjoyed. Don't know if old Etonians will agree, but we can recommend it.
The 5ml touch of almond/kernel works beautifully and harmoniously, adding depth to the spirits, wine, herbal and fruity characters of the gin and Lillet. Recommended.
I’m surprised Difford’s Guide doesn’t also feature the Harrovian cocktail, from the Savoy Cocktail Book, as Harrow is supposed to be the rival school to Eton!
Agreed, it's a glaring omission. I've added a draft Harrovian recipe to our Early Access Cocktails ahead of perfecting in the coming days and photography.