Green’s Dictionary of Slang

sex appeal.

1928		J.P. McEvoy Showgirl 99: I wish Denny had some of his S.A. Denny is just too sweet and orderly to be thrilling.
1929		S.J. Perelman Dawn Ginsbergh’s Revenge 195: Paul, as the photo reveals, is just crawling with s.a.
1937		P. Cheyney Dames Don’t Care (1960) 52: You never know where you are with dames — especially when they got sex-appeal. The more SA a dame has got the more trouble she causes.
1940		A. Christie Sad Cypress (1954) 98: She wasn’t one of these girls who are all S.A. and IT.
1951		Green & Laurie Show Biz from Vaude to Video 571: S.a. – sex appeal.
2003		K. Cage Gayle.