nos - 'New Old Stock' generally refers to a 'lot' or 'bulk' item(s) that have been discovered tucked away from an old store or business.

outer box is dirty from shelf wear- made of a better grade of plastic than the new ones -

Auxiliary contacts can serve as additional motor starter. Here is some additional information about Square D Auxiliary Contact. For Use With: 2 and 3 Pole, 120 Amp Contactors, Number Of Contacts: 2.