I googled for an answer and found a mystery! My grandfather who was born in 1898 (in WVa.) and used to always say "Thank you said the kind old lady as she shook her wooden leg" when picking up passed cards during a game of hearts. When I asked him what it meant he said " I'll tell you when you get older Billy" but he passed away before I got old enough. I assumed it was the punch line to something off color. It looks it will ever remain a mystery now!