El Bar Americano en España by Pedro Chicote (1927, p.109)

1 tablespoonazúcar en polvo base
0.5 liqueur-glasscoñac — Source uses dash shorthand for the repeated unit.base
0.5 liqueur-glassron base
té hirviendo — Used to fill the drink.dilution
1 slicerodaja de limón con clavos — rodaja de limón incrustada de cuatro clavosgarnish
  1. Build in a grog glass with sugar, rum, cognac, and the clove-studded lemon slice.
  2. Finish with boiling tea.

370 Recettes de Cocktails by Jean Lupoiu (1928, p.10)

0.2cognac — Cognacbase
0.2rum — Rhumbase
boiling water — eau bouillantedilution
0.25strong black tea — forte infusion de thé noirdilution
1lemon slice — tranche de citrongarnish
0.17curacao — Curaçaomodifier
0.2gum syrup — Sirop de Gommesweetener
  1. Prepare the concentrate in advance by mixing the rum, cognac, curacao, gum syrup, and strong black tea.
  2. To serve, pour as needed into a grog glass, add a slice of lemon, and fill with boiling water.

Garnish: Lemon slice

Cocktails by Pedro Chicote (1928, p.281) — Americano

0.5 copitacognac — Conacbase
0.5 tablespoonpowdered sugar — Azucar en polvobase
0.5 copitarum — Ronbase
Boiling tea — Te hirviendodilution
1 sliceClove-studded lemon slice — Rodaja de limon con clavosgarnish
  1. Build in a grog glass, fill with boiling tea, and serve hot.

Garnish: Clove-studded lemon slice

This matters because it preserves a mixed rum-and-cognac grog branch in Chicote's hot-service chapter.

The defining service detail is finishing the glass with boiling tea rather than plain hot water.

The Artistry of Mixing Drinks by Frank Meier (1936, p.65)

1 slicelemon — Lemon sliceacid
1 glassAmerican grog — American Grogbase
water — Boiling waterdilution
  1. Pour the spirit into a heated tumbler, add a slice of lemon, top with boiling water to taste, and serve.

Ice: Ice

See also: Spanish Grog, Whisky Grog

Source gives batch proportions for one litre and then directs hot service to order.