Carbon brushes don't have any idea whether they're in an automotive application, a skilsaw, or a vacuum cleaner. Check with an appliance repair shop, and try to match up a brush that's about the right size and length. If it's a little too big, a file will take it down to size quickly. If the coppper wire attached to it isn't exactly right, clip it off close to the old brush and solder the original lead onto the new brush lead. Sometimes it's necessary to get creative with this antique stuff!
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!