Looks good so far! My only advice would be, make sure the paint is COMPLETELY cured before taking the edges down, and when you do take the edges down, I'd use a razor blade or X-Acto knife rather than sandpaper. Ideally an X-Acto knife with a curved blade so you can catch just the edge without scratching the paint surface or the key by accident.
Drag the blade backwards along the paint ridge several times in a scraping motion rather than "cutting" then edge in a forward motion.
Hope I'm not too confusing, good work and good luck!
CZI