Green’s Dictionary of Slang

brandy-latch n.

(Polari) a cubicle in a public lavatory, used for gay sex.

[UK]P. Baker Fabulosa 290/1: brandy latch, a toilet cubicle.
[UK]R. Milward Man-Eating Typewriter 108: [T]he manky pogi brandy-latch in the Holloway Road. Khazi with the glory-hole.