Tape it off, sand it and get some black spray paint, but it is going to be hard to make the paint stick to the chrome when gravel hits it.

Nice looking solid car and welcome to the Cutlass club. The interior is real nice, not too many in those years had buckets so that's a major bonus. The roof looks like its toast but those years didn't rust underneath the vinyl as bad as the older ones like mine. Good luck with it.