The Fanciulli Manhattan is an interesting yet flawed drink, in my estimation. Why do I say this? I'm fond of all three ingredients, but when put together with the given recipe, the small amount of Fernet Branca overwhelms the other two ingredients. I used Maker's Mark bourbon and Dolin sweet vermouth for the other ingredients. The resulting cocktail I rated as 3.5.

My suggestion is to use either an overproof bourbon (such as Baker's or Basil's) or a bourbon with more overtones than Maker's Mark (such as Dickel's 8 year Tennessee sour mash, or Jim Beam black). The other alternative is to use a quality rye instead of the bourbon. For now, I'm calling the Fanciulli Manhattan a work in progress, and hope that with the changes I suggested, it will become a cocktail that will be rated consistently at a 4.0 or higher.

Curation note: I have updated this cocktail, correcting the name from "Fanciulli Manhattan" (not the name in sources) to Fanciulli while noting the proportions are a modern variation. I have added the Liquor.com link for a common variation w/2 oz of whiskey. The original recorded in 1931 had far more fernet, and could be either bourbon or rye. I have been experimenting with some of what claims to be the original fernet, Fernet Vittone (ca. 1842 vs. 1845 for Fernet Branca) and made a variation I like with 1.75 oz Bulleit Bourbon, 3/4 oz Cocchi di Torino, and 1/2 oz of Fernet Vittone. Fernet Vittone is drier, with a less aggressive flavor than the saffron/menthol of Fernet Branca.

(Made with pomegranate molasses for grenadine)

hm. I liked what is going on here - I'll probably do some fussing with the proportions.

on second thought: I like it just the way it is. I'll make this again.

Very lovely, floral drink with Plymouth Gin.  Going to try the next one with Beefeater 24...

Delicious, even when made with a rather strange looking lemon that I filched from my neighbor's tree.

The drink is not necessarily chilled.
Many variations are appropriate too.
The one as described in the recipe.
Another, the same without ice. And another version more like a caipirinha, with more lime and with or without ice.

Some recipes allow nearly only peel, not flesh. Small piece, no ice, little syrup. Lot of rhum.

This is really intriguing. I've never seen the Maurin Quina before and will definitely look for it. I'm wondering what would happen if Cherry Heering or Combier Rouge were substituted for the cassis here.

I tend to think about cocktail development in terms of flavor or aroma accords. In this cocktail, I was thinking about the bitters first - they're fruity, with a chile spicyness and typical bitter notes. That led me to Cassis, which is fruity + a woody bitterness, which led me to Rye, which has a green, woody bitterness as well. Maurin Quina is cherry + almond + some interesting bitter notes, and the rinse of Creme de Cacao is meant to mimic the 20th Century cocktail, as well as to tie in and harmonize the other flavors, all of which go well with chocolate. This is still in the theoretical phase, as Maurin Quina is a special order only thing where I live ;) 

But to answer your question... I think that other cherry liqueurs might be a good substitition, as long as they have a bitterness to them. You might also want more lemon juice in the cocktail to make up for the loss of acidity in the cherry liqueurs.

So I'm busy today. My likker store actually sourced a bottle of Maurin Quina for me, and I made the drink as written (the bitters are dropper instead of dash). I like this, if I do say so myself. It tastes like a good left bank Bordeaux in a weird way, with woody notes forward, cassis and red fruit in the midpalate, then the bitterness of the Maurin Quina mixed with the chile-accented bitters on the finish. I think a bit of extra shaking is a good thing as it brings out the brambly Cassis more.

Quite tasty, but I'd cut the bitters to one dash, otherwise it overwhelms the other ingredients.