I'm going to try and start working on new clear windows for our DD Walkmans since I can't find replacements I'll probably get to manufacture them myself if I can I'm going to do my research in it
Here's a recent thread about another model http://stereo2go.com/forums/threads/design-on-acrylic.3600/#post-29586 It's probably Acrylic or Polycarbonate, both come in sheets and are clear. We have a ton of places in town I can buy it off the shelf; I don't know if you have the same distribution over there. You can cut both using woodworking equipment or if it's thin enough sheet, I think you can score and snap, like glass. Check out the thread I posted on Adam Savage's Walkman Build, I think he put a window in it. If you need help I may be able to post some fabrication methods, I still have a few books lying around when I sold custom plastic fabrication.
First I'm going to try and find very thin acrilic or policarbonate plastic Then I'll start taking measurements to see where I can go from there