Try brushes for electric tools such as routers, skilsaws, electric drills, etc. Most brushes are just chunks of carbon with a piece of braided wire attached, and it one is a little oversized, a file works nicely to make it fit. I've adapted generator brushes to some non-standard applications many times- - -take one a little bigger than needed and file-fit it to the brush holder. Depending on the size of the original, a set of brushes for a Dremel tool might even work, and I just saw a set of them at Walmart earlier today. If the conductor and/or spring isn't right. just solder on an extension.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!