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!)