How do you show the glass over the TSU on the Cobra?

Maybe I don't understand your question. The port side of the TSU does have a flat clear glass cover. You can replicate that with clear plastic. Inside the TSU (underneath that glass) is a whole bunch of wire bundles, bits, and pieces. Chief among these are three cylindrical objects that dominate. Two of them look like camera lenses - one big and one small (Hi mag and Lo mag). You can replicate these with a short lengths of clear sprue painted black around the circumference. Between these two (stacked vertically) is a small red lense (IR sensor).

I pained the area under the "glass" with copper metallic paint and then I used some film negative, coated with Future instead of the kit piece to cover it. I like how it turned out. It may not be the most accurate, though.

Hopefully these shots will help anyone wanting to detail the inside of their TSU. As you can see, the FLIR window (starboard side) cannot be seen through at all. A gloss black or a couple coats of Future over it would work great. For the DVO window, you could open up the kit part, install a clear styrene window, and detail the inside of the "bucket" with various wires and bits to make those two large camera aperatures.