What's the best way to clean this old GM nos Distributor Gear ?

Engine: Early 1954 235 6-cyl. with small cam journals Forged Steel camshaft.
So, the distributor gear is hardened steel to match the cam.

See: PIC

http://i669.photobucket.com/albums/vv57/glp0329/DistributorDriveGearGMNOS_zpsfb522666.jpg

I'd like to use this nos gear but don't want to hurt the fit on the distributor shaft.

Any suggestions appreciated.

Thank You,
George

1954 3600
A big help to many on the Bolt
Now cruising in
The Passing Lane