Franco Giorgi by Quadrifoglio

Check completed listings on eBay. There are serving platters selling for a fiver each, and a set of four soup bowls unsold for under £6. So not worth much

That is a common problem with Italian Ceramics manufacturers. A lot of information in the mid to late 20thC was lost for one reason or another. Only individuals like Guido Bitossi are actively researching their family and company history. Most aren’t bothering, especially when it’s simply mass produced tableware. If there’s an element of Art Pottery in the company’s output - like Bitossi - then collectors are more interested and there’s more information available online and in collectors groups