Good news is - it rewinds. Meaning the flat steel spring is fine. A few threads about trouble-shooting, refurbishing, and adjusting cordwinders have been posted this year. A search of the 2008 Vintage archives subject threads is the way to go.
Jim, the usual fix is to remove the cordwinder unit and simply loop a few more cord turns around the cord reel until it fully and smartly retracts under test, before re-assembly. You can do this without having to disassemble the cordwinder unit or remove the plug from it's side hole.
Dave