Heh, sounds I don't have to check anymore 
I do have the "narrow" version for a standard Nintendo cab, not the wide-body....but I guess they used the same process for all...
i also have the narrow one.
will start in a few hours...
ok... startet with my "project glass".
sanded the nasty deep scratches with 400 sandpaper.
i did spray a little bit of water on the surface though. after those scratches were gone i took the 1000 sandpaper and went over every part again.
since I am still waiting for the 2000er paper which is definately needed to get better results I decited to polish the sanded areas of the bezel and the result was good so far. those parts are still a bit milky but i am quite sure that the 2000er paper will do the job.
the really bad scratches are gone and the milky parts are not that much of a problem.

thank you guys for all your help.
greetings from trier!
stefan