Maybe fill the scratches with a filler (like Bondo for auto-body repair or JB Weld which comes in much smaller quantities), then go over it gently with a lint-free cloth moistened with isopropyl alcohol to wipe off any excess filler material and smooth it down. I would mask the entire machine except for making a hole around the scratched area. Make a similar sized hole on a piece of cardboard about an inch or so bigger than the scratch on all sides and hold it about 1" above the area to be painted. Then using matching color spray paint, spray from a good sized distance about 20" or so. This should give the paint a fine orange-peely textured finish that will hopefully blend in. The cardboard with the hole in it is so the paint will lay with a feather-edge so there's no sharply defined edge between plastic and painted area.

If you have any scrap plastic, you may want to experiment.