I found this recipe on mrbostondrinks.com.

gin, dry vermouth, maraschino liqueur, grapefruit juice⁣
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I couldn’t find any history on this cocktail, other than it is from The Savoy Cocktail Book published in 1930, as well as Classic Cocktails from the Prohibition Era.⁣
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This drink is pretty much a martini, aside from the tiny bit of maraschino liqueur (1/4 tsp) and grapefruit juice (1/2 tsp). I’ll tell ya, that tiny bit of sweetness really helps it go down smoothly! ⁣