Green’s Dictionary of Slang

legs, occas. in sing. (see cite 1919).

1914		Sport (Adelaide) 14 Mar. 4/4: Maggie and Winnie M have fine ‘Ham and Eggs’.
1919		Truth (Brisbane) 28 Sept. 2/2: ‘Aussie Hater’ seems to have had his ham and egg badly pulled by some ginger Aussie twist, but why should he condemn the lot for the needle and pins of one?
1924		Mail (Adelaide) 16 Feb. 1/4: This is how a class of rhyming ‘slangsters’ [...] discourse on anatomy:— Legs— [...] ham and eggs.
1932		‘P.P.’ Rhy. Sl. 11: Have a ‘butcher’s’ at her ‘ham and eggs’.
1948		Smith’s Wkly (Sydney) 25 Dec. 6/1: This is a sheila with very sensational ham-and-eggs, but far too young to be kicking them about the stage.
1960		J. Franklyn Dict. of Rhy. Sl.
1967		‘Whisper All Aussie Dict.’ in Kings Cross Whisper (Sydney) xxxv 6/2: ham and eggs: Legs.
1970		N. Beagley Up and Down Under 80: Look at all the good sorts walking past, look at the ‘ham and eggs’ (legs).
1989		H. Rawson Dict. of Invective (1991) 41: In other instances, the speaker may go so far as to articulate the rhyme word, e.g., ham and eggs, legs.
2001		D. Looser Boobslang [U. Canterbury D.Phil. thesis] 83/2: ham and eggs n pl. legs.