Vintage Primastone Stoneware Mustard Yellow Set of Three Cereal Bowls

This is a beautiful set of three bowls labeled Primastone made in Japan stoneware. I have found no information on these bowls and only information shows Noritake also had Primastone collection but these are not marked that. Beautiful little bowls and only minor color imperfections and are not chips. I have included pictures. Thank you for looking and I am open to reasonable offers or bundle deals with my other items. (Cross posted)