Italian pottery was very popular here in the USA from the 1950s - 1970s, and there are many different types and makers including Deruta, Bitossi, Gambone, Marcello Fantoni, Bagni, and many more. The ceramics were so popular that many lesser quality companies made products with "Italy" along with numbers to mimic the higher quality brands. That being said, many of the lesser brands are charming and popular as well though they would not command a price similar to a high-quality piece.
Try to identify your items. You did not say if there was a manufacturer's mark. This will take some time. Describe the piece in Google images. See if you find something similar and go on from there.
There are online forums dedicated to Italian pottery that may help you.
"Alla Mode Italian Ceramics of the 1950s - 70s," by Mark Hill is a book that you may want to consult.