L'Art du Shaker by Dominique Migliorero (1925, p.19)

2 dashAngostura bitters base
0.67 partHolland gin — Holland gin (Schiedam)base
0.33 partItalian vermouth — Vermouth Italienmodifier
1 zestlemon zest — Lemon zestother
  1. Stir very cold, strain into a cocktail glass, and serve with expressed lemon zest.

Garnish: Lemon zest

The source explicitly labels this as the author's recipe.