Well, I finally got around to looking into this word, and what should I find in Partridge's Dictionary of Slang but crinkum-crankum quaintly glossed as: "The pudendum muliebre: ca. 1780-1870. Grosse, 3rd ed. Ex the S.E. sense (cf. crinkle-crankle), a winding way. Cf. crinkums, q.v. —2. In pl. (crinkum-crankums), tortuous handwriting.: colloq. (-1887)." And under crinkums "A venereal disease."