Magnolia

Harry of Ciro's ABC of Mixing Cocktails by Harry of Ciro's (1923, p.61) — Harry of Ciro's 1923

1. Shake well and strain into medium-sized wine glass.
2. Fill the balance with Champagne.

This matters because it preserves another egg-and-Champagne service branch that sits between flip logic and sparkling cocktail service.

The key service point is the shaken base finished with Champagne in the serving glass.

L'Art du Shaker by Dominique Migliorero (1925, p.40)

1. Shake hard, strain into a medium balloon glass, finish with Champagne, and serve.

Barflies and Cocktails by Harry McElhone and Wynn (1927, p.50) — Barflies 1927

1. Shake well, strain into a medium-sized wineglass, and fill the balance with Champagne.

This matters because it preserves another egg-yolk-and-Champagne branch in the interwar hotel-bar field.

The Artistry of Mixing Drinks by Frank Meier (1936, p.73)

1. Shake with ice, strain into a fizz glass, fill with Champagne, and serve.

Ice: Ice