I tried three thick coats of gloss black paint, covered with three coats of clear ultra-tough gloss varnish...but the surface was still able to be marked with jewelry - metal watch straps in particular.
In the end , rather than continually touch up the control panel, I covered the top with loudspeaker cloth cover. This was a black, glossy thick vinyl material that was non-adhesive. I covered the entire surface with liquid nails, attached an oversized piece of cloth to it, let it dry for 24hrs, and trimmed it to size.
So far, this has been fine - 2 player Track and Field thrashings have not made a mark on it - and there are no finger print smears to wipe away either.
As for the button layout...my six buttons are layed out as:
123
456
But as Tiger-Heli says, you could map individual games to your tastes...