If you turn a piece of round stock to be a close fit for the rocker arm pivot hole, mount it vertically on your tool post holder, and rock the carriage feed back and forth, you can follow the contour of the rocker tip by turning the rocker against the disc by hand, and moving the carriage back and forth with the hand wheel. Just try to follow the existing radius of the tip and smooth out any wear spots.
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!