You can actually remove the rusting bezels by prying it gently off the body of the tach with a small screwdriver; however, you have to fold the whole ring back and upward off of the plastic inner body. If you do it this way and try to pry it back onto the body, it will end up looking "rippled." FAR easier to tape and paint. (I had a spare dead tach I experimented on.)
Scheherazade
'86 VN750
MF Battery, Iridium Plugs, RR relocated, Voltmeter, 170/80/15 Kenda Kruz rear tire, DIY Samsonite hard bags, DIY shaved seat with Beaded seat pad ('cause that's how I roll) and the dreaded STATOR CHANGE.
Shining Black Bess '86 VN750, retired for parts after a fried stator and being knocked (kee-runch) in her parking spot.