... If the chrome is bad, then the only solution is a re-paint.
I tried painting the OEM mirror stalks on one of my R65s. For me, an exercise in frustration, it was.
Paint will not stick for long on chrome. Surface tension will keep it in place for a little while but the first chip... well, I tried it.
The stalks were pitted from rusting. I sanded and wire wheeled 'em. Back again with various grades of Wet-or-Dri. Even filled the "chuck holes" in the chrome prior to painting. Invested way too many hours in a fruitless quest for improved cosmetics.
Bought new mirrors that are way better than the obviously painted chrome stockers. I will never try that again as it just doesn't provide a long lasting fix. First chip and people notice the ghetto fix. But YMMV. Bets of luck. My new mirrors cost less than the materials and wasted time I expended on a bad job made worse. :-/
Monte