Nino,
Try some Plexus, perspex polishing compound, I think I bought some from Autobarn last time.(around $20)

I used this on the Caddilac restoration a while back to remove the marks on the speedo cluster area.

It worked a treat!

Cheers Angelo

+1

The best. Warm the plastic up first (in hot water) - makes it easier to cut back. (Logically!)

Anybody stuck one of these (playfield windows) in a dishwasher? I wonder if it would clear up like ramps do?