1982, Lawrence Durrell, Constance, Penguin 2004 (Avignon Quintet), p. 633:
I had warmed under the smiling gaze of this military young woman who wore her small lifeboat hat (these were, I afterwards discovered, known as cunt-caps among the girls themselves) and smoked her ration of tobacco, though she always refused coffee.
I hated it – I preferred to wear the gook cap because the cunt cap had DUMMHEIT embroidered all across in black, in an elegant cursive, really swanky and stylish.
1989, Paul Fussell, Wartime, Oxford University Press, p. 92:
The soldier's overseas cap, the one that opens up along the top, is called a cunt cap: it's hard to imagine any other piece of conventional headgear, like a policeman's visor cap or a bishop's miter or a motorcyclist's helmet treated automatically with such obscene disrespect.