I'm sure a large majority of stovebolts have at least a little of this sort of wear/noise issues. Some folks think they're supposed to sound like that. It won't hurt to run it until it's convenient to do a little investigating. BTW, being slightly noisy is much better than being "quiet and too tight" which could lead to burned valves and/or a miss from low manifold vacuum.
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!