Put it on Craig's list. Price it at $20 or $30....
Sounds like it's in pretty rough shape, but someone will take it for the $20 or $30 that you'll list it for, take it home and make it work. Don't junk it...you could make someone's day with it!
Some folks can't pay a lot for a machine, but they're willing to put sweat equity into it in order to have a nice machine that works. Could be someone's only chance to own a treadle...