Green’s Dictionary of Slang

a derog. term for an East Asian person; also as a nickname.

1948		J.L. Riordan ‘A.V.G. Lingo’ in AS XXIII No 1 30: Life among our little brown brothers—who were sometimes less affectionately referred to as slopies, coosies, or flange-heads—was much different from that among the Wogs in India.
1967		(con. 1930s) R. McKenna Sons of Martha 123: Flangeface Hogan stood watching.