About 80 Pieces of antique china

I have a bunch of antique china that was found in my mother in laws basement. I found the china wrapped in news papers dated from 1978 so I would expect they are older than that. There are about 80 pieces total. Things like; plates, saucers, gravy boats, tea cups, serving dish, and more. The markings on the backs vary. Some say “national china Salineville OH” others say “National Dinner Ware with an “N” in a shield then “La Rosa”. Some say warranted “18 carat gold handle” pictures show the whole set. All  pieces have the same design