Playing through I found a harmonica at the one gunslinger's hut and believe I fenced it without thinking. Later in the game, Sadie requests one and Arthur says that he did find one before, but will need to keep an eye out for another. All the guides only show the gunslinger's hut as the location of the harmonica to complete her fetch request, but there has to be more out there, right? Or am I screwed and unable to complete this fetch quest? Any insight would help.