You've got the right quest, the damsel in distress is indeed Melody Silver. Nobody else will do.If you rescued her but never took her back to Wilbur Humphrey, she may still be with you. Have a good look at the borders of the pictures of your NPCs. If there's a little arrowhead about half way up on one side or the other, try clicking on it and see what turns up. If that doesn't work, I think you're screwed. 
There's one other thing you could try, and that is to go and see the hermit in Ironfist. That's a very long shot, though.
