The original Paper Plane was first created back in 2007 by Sam Ross for the Violet Hour in Chicago. He is also well known for making the smoky Penicillin cocktail.
The recipe was first made using Campari but changed to Aperol in 2008 when the cocktail being served at Milk & Honey in NYC.
I substituted Montenegro in place of the original recipe's Amaro Nonino - although it doesn't have the same citrusy profile of Nonino, it does make a good alternative (both cheaper and more readily available).
The Paper Plane is also referred to as a Last Word riff despite not having ANY of the original ingredients (Gin, Green Chartreuse, Maraschino Liqueur & Lime Juice).