It is entirely possible that it has more than one source. It's not beyond the realms of possibility that more than one person independently thought of compounding "I'd" and "rather" and then (as the lettered one put it) nominalizing and pluralising (and possessivising and subjunctivising!) it as "If I had my druthers."

Last edited by The Pook; 03/31/2008 11:03 PM.