Tractor is an M 5140HD, First I am not sure if the cover is plastic or glass it is covered in thick dust. I would guess I should clean it with a damp wet micro cloth as if it is plastic I do not want to scratch it. How do you clean yours
For removing fine scratches and cleaning plastics of pretty much any kind, I use the products from Novus: Novus Plastic Polish 1, 2, & 3. Novus 3 is for somewhat deeper scratches while Novus 2 is for removing finer scratches and haze. Novus 1 is a cleaner/wax. An excellent line of product that will give you close to optical glass results if used properly and your fingers don't give out from the rubbing and polishing required.
If your scratches are pretty deep you may need to start out with sandpaper and wet sand using progressively finer grits (to 1500 -2000, or finer) before using the Novus products. The Novus products will also put a sheen or gloss finish on painted surfaces, too. Regards, David