See Chicago Tribune Article here.   “The recipe came to us by way of Colonel Harland Sanders’ nephew, Joe Ledington of Kentucky. He says he found it in a scrapbook belonging to his late Aunt Claudia, Sanders’ second wife. Ledington, 67, says he used to blend the spices that went into his uncle’s world-famous fried chicken, and the recipe in question is the real deal.

See article where they sprinkled Accent (MSG) lightly afterwards to make it like sold today.  Today they admit they use MSG.

Testing by the Tribune’s kitchen is presented here. That includes; “With the oil temperature just right at 350 degrees, the chicken soaked in buttermilk and coated just once in the breading mixture”

Wash was 1 egg to 1 cup milk per a poster on SMF.  Ts means tablespoon based on the taste test at the Tribune.