Here's a version of the trackball and mounting plate flush mounted on the CP, with Lexan and artwork on top.
Basically, I set my router depth to match the depth of the top of the mounting plate (about 1/8" of an inch), and routed the outline of the plate. When dropped into the recess, it sat flush with the top of the CP. The artwork was placed on the panel and mounting plate (covering it) and then Lexan on top of it.
I don't have a picture of the 'naked' CP after I had routed the top out, but I hope this helps...