Not forgetting "At Last the 1948 Show" and "Do Not Adjust Your Set", both precursors of Python. The former had Tim Brooke-Taylor, Graham Chapman, John Cleese, Marty Feldman and Aimi MacDonald. The latter had David Jason, Eric Idle, Terry Jones, Denise Coffey and Michael Palin.
The Four Yorkshireman sketch from the Pythons was a direct word for word nicked piece from "At Last the 1948 Show", but it was written by the actors who went into Python.