If you use cast acrylic instead of plexi, there's less need to worry about stress buildup, it machines really nicely. No need for flood cooling either if you keep the cuts nice and light.

Choowy, if you ever decide to go down the backlit/edgelit route - it'd be worth getting a quote from one of the many CNC shops offering their services online. I've found the prices to be far more accessible than I thought they would be.

Hey Wasp! That thing looks awesome - I bet there's a real sense of occasion when you climb into the pilots seat!

EDIT: Formatting

@Lipfert: I don't create individual lamp cavities or wire channels. I machine the whole interior out down to a depth of .2" (given a .25" thick panel). A typical Type 5 panel consists of a fully machined panel with a very thin PCB lamp board that screws to it. The first panel I built along the Type 5 lines did use lamp pockets - you can see what I did here:
http://www.f15sim.com/pre_blog_news-1.html

@Choowy: Is there a way you could post a pic of the Mech cockpit with you or someone else standing next to it? It would help in getting idea of how large it is beyond a simple measurement.

g.