thanks! unfortunately the amp is already all packed to head off to college so i am forced to be more mysterious than was my intention...
the top part, if you were to see it, would have a color and finish kind of similar to that on one of these:
http://www.seas.gwu.edu/~ecelabs/labtour/ascope.html
amazing what a ruler, some clamped wood guides, a jigsaw, and a lot of cursing can get you :) still have 10 fingers...
anyway as soon as i get back i'll plug it in and switch on the heaters to show you some glow.