Green’s Dictionary of Slang

bundle of socks n.

(Aus.) the head.

1902		Bulletin (Sydney) 18 Jan. 16/3: A heavenly plan [...] fancy-sashed the girl-abductor on his bundle of socks.
1945		Baker Aus. Lang.
1972		Dodson & Saczek Dict. of Cockney Rhy. Sl.
2002		Pete’s Aussie Sl. Home Page 🌐 bundle of socks: think-box, the head.