I will paint it black. It's not solid wood and doesn't look too nice in daylight the way it does now.
I have polished the last keys on Sunday and I reassembled the keys on Tuesday night after having cleaned the contacts. The next morning my older son was astonished that the keyboard looks like new now.

You have to take a close look to see that there has been wear and tear and burn marks.
Yesterday I ordered a few parts to fix the faulty switches. I also managed to purchase a switch cap for a Roland TR-707 (at syntaur.com) that seems to fit without problems; it will only look a bit different.