Last month I was in Mike's Camera in Boulder -they had a heap of Hove Leicaflex manuals for thirteen dollars. I can't remember which model Leicaflex they were for.
Here's a freely available online copy of an SL manual at Camera Manuals Online.
Doug Herr has a page on the original Leicaflex.
Like Clogz says, how much of a manual does a Leicaflex need?