If the brass inlay is corroded, there's no good way to clean the chip, Pete. You can use vinegar to remove the copper salts but it will leave the surface pitted and not smooth. If you polish it with an abrasive, the scratch lines will be obvious on the smooth brass. You might try a polishing compound on a wheel that spins with the chip center as its axis. The chip might then look like the "concentric circle" variety of these Bud Jones chips. I've not tried this, though.

Or, you can just consider this one of the marks of an old chip <g>.

DonL