T Limoges was a USA importer from 1950 to 1990. The company imported 

porcelain items from different manufacturers in France, Italy & Germany. 

 Mediterranea is the company in Italy that produced the item for T Limoges.

"Antichi Mestieri L'Arrotino" translates from Italian "Antique Crafts L'Arrotino".

 L'Arrotino translates The Knife Grinder.

The item does look like a medallion to be added to another item. 

The image appears to be from the book "Uses & Customs of Naples & 

Outlines Described & Paintings" by Francesco de Bourcard published