Theres no need to resurface the whole tip, just remove the high spots. I've worked on a lot of stamped steel rocker arms just using a scotch-brite sanding disk mounted in a drill press. At high rpm, a couple quick passes can really smooth out the tip. NextI use a flap wheel with alternating flaps scotch-brite / smooth emery cloth. Not sure where I got the wheel from, but it really leaves a nice finish.
