Harry of Ciro's ABC of Mixing Cocktails by Harry of Ciro's (1923, p.81) — San Sebastian

0.5 limelime juice — Juice of half a lime.acid
1 glassbrandy base
1 teaspoonfulCitron syrup — Syrup Citronbase
Soda water — Sodadilution
1 glassPonche-Soto modifier
  1. Shake well and strain into medium-sized wine glass.
  2. Fill the balance with soda.

This matters because it preserves a named San Sebastian long drink in the London 1923 layer.

Barflies and Cocktails by Harry McElhone and Wynn (1927, p.75) — San Sebastian popular drink

0.5 limelime juice — Juice of half a Limeacid
1 glassbrandy base
1 tspfulCitron syrup — Syrup Citronbase
Soda water — Sodadilution
1 glassPonche-Soto modifier
  1. Shake well and strain into a medium-sized wine glass.
  2. Fill balance with soda.

This matters because it preserves a regional Ponche-Soto long drink rather than flattening the late interwar field into only gin and whiskey branches.

See also: Royal Smile, Scotch Highball