The Up-to-Date Bartender's Guide by Harry Montague (1913, p.40)

1 piecelemon peel — Twisted on top.acid
1 jiggergin — Substituted for brandy.base
0.25 whiskey glasshot water — Fill one-quarter full.base
  1. Substitute gin for brandy and proceed as for Brandy Skin.
  2. Serve hot with twisted lemon peel.

Garnish: Lemon peel

Source is explicitly substitution-based.

See also: Gin Sour

Source says to substitute gin for brandy and proceed as for Brandy Skin.