I just wanted to share something. My CP has lexan on the surface. Over the last 4 years, the lexan has "grown". It is expanding outwards, and it it "bowing" upwards.
I used a hand planer on the edge of the lexan. I set the depth of the blade very shallow. IT WORKED GREAT! The planer would take off a little sliver the whole length of the lexan edge. No cracks/spidering/etc.

Additional pics of the CP can be found on this thread.
http://forum.arcadecontrols.com/index.php?topic=80426.0 (Yes, I was very successful with the planer. However, I bungled the artwork!)